Service Manual Trucks - АренаАвтоаренаавто.рф/docs/VOLVOVEB.pdfService Manual...

Service ManualTrucks

Group 250-610

VOLVO Engine Brake

VE D12, D12A, D12B

PV776-TSP0250610/2

Foreword

The descriptions and service procedures contained in this manual are based on de-signs and methods studies carried out up to February 2000.

The products are under continuous development. Vehicles and components producedafter the above date may therefore have different specifications and repair methods.When this is believed to have a significant bearing on this manual, supplementary ser-vice bulletins will be issued to cover the changes.

The new edition of this manual will update the changes.

In service procedures where the title incorporates an operation number, this is a refer-ence to an V.S.T. (Volvo Standard Times).

Service procedures which do not include an operation number in the title are for gen-eral information and no reference is made to an V.S.T.

The following levels of observations, cautions and warnings are used in this ServiceDocumentation:

Note: Indicates a procedure, practice, or condition that must be followed in order tohave the vehicle or component function in the manner intended.

Caution: Indicates an unsafe practice where damage to the product could occur.

Warning: Indicates an unsafe practice where personal injury or severe damage to theproduct could occur.

Danger: Indicates an unsafe practice where serious personal injury or death could oc-cur.

Volvo Trucks North America, Inc.Greensboro, NC USA

Order number: PV776-TSP0250610/2

© 2000 Volvo Trucks North America, Inc., Greensboro, NC USA

All rights reserved. No part of this publication may be reproduced, stored inretrieval system, or transmitted in any forms by any means, electronic, me-chanical, photocopying, recording or otherwise, without the prior writtenpermission of Volvo Trucks North America, Inc..

ContentsGeneral .................................................................................................... 3

VOLVO Engine Brake (VEB) ................................................................. 3

Tools ........................................................................................................ 5VOLVO Engine Brake, Special Tools ..................................................... 5

Other special equipment ..................................................................... 6

Design and Function ............................................................................. 7Engine Brake ......................................................................................... 7

Exhaust Brake ..................................................................................... 7Compression Brake ............................................................................. 7Control Valve (VEB) ............................................................................ 8Camshaft (VEB) .................................................................................. 9Exhaust Rocker Arms (VEB) ............................................................. 10Non-Return Valve (VEB) ................................................................... 10Rocker Arm Plunger .......................................................................... 11

Engine Operation ............................................................................ 11Compression Braking ...................................................................... 11

Engine Braking .................................................................................. 12Control System, D12 and D12 A .................................................... 12Exhaust Brake ................................................................................. 13Compression Brake ......................................................................... 14Induction Phase .............................................................................. 14Decompression pPhase .................................................................. 14

Troubleshooting ................................................................................... 15Engine Brake, Fault Tracing ................................................................ 15

VEB Diagnosis and Troubleshooting ................................................. 15Electrical Troubleshooting ................................................................. 16

Special tools: J–41132 .................................................................... 16Connecting test equipment ............................................................. 16Voltage measurement ..................................................................... 17Resistance measurement ............................................................... 17

Mechanical Troubleshooting .............................................................. 18Conditions ....................................................................................... 18

VEB Troubleshooting, Order to Follow .............................................. 191 ...................................................................................................... 192 ...................................................................................................... 193 ...................................................................................................... 194 ...................................................................................................... 19

VEB Fault Symptoms ........................................................................ 20Fault symptom 1 .............................................................................. 20Fault symptom 2 .............................................................................. 20Fault symptom 3 .............................................................................. 20Fault symptom 4 .............................................................................. 20Fault symptom 5 .............................................................................. 20Fault symptom 6 .............................................................................. 20Fault symptom 7 .............................................................................. 20

Low Engine Braking Effect (VEB) ..................................................... 21Check Before the Test: .................................................................... 21Test Equipment, Installation ............................................................ 21Test-driving and Measuring ............................................................. 21Brake Test ....................................................................................... 22Evaluation of the Brake Test ........................................................... 26

Engine Brake, Checking ...................................................................... 27

1

Solenoid Valve, Compression Brake, Checking .................................. 29Exhaust Brake, Electronic Checking ................................................... 30Exhaust Brake, Mechanical Checking ................................................. 32Oil Pressure, Compression Brake, Checking ...................................... 36Exhaust Temperature, Checking ......................................................... 40Rocker Arm Roller, Checking .............................................................. 46

Service Procedures ............................................................................. 49Rocker Arm, Overhaul ......................................................................... 49Solenoid Valve, Compression Brake, Replacement ............................ 51Control Valve, Engine Brake, Replacement ........................................ 53

Operation Numbers

2

Group 25 General

GeneralVOLVO Engine Brake (VEB)

Successful troubleshooting of the VOLVO engine brake system requires information re-garding system design and knowledge of how the different components function inrelation to each other.

W2002155

1 Camshaft2 Shutter3 Exhaust pressure governor

4 Rocker arm5 Control valve6 Oil pipe

The description, operation and service of the Volvo En-gine Brake is detailed as follows:

The Troubleshooting section is subdivided into ElectricalTroubleshooting and Mechanical Troubleshooting.

Refer to this information along with the description andoperation information when performing troubleshooting.

3

Group 25 Tools

ToolsVOLVO Engine Brake, Special Tools

Servicing the Volvo Engine Brake (VEB) requires the following special tools. The toolsare available from the Parts Department of Volvo Truck North America, Inc. Unless oth-erwise noted, all tool numbers are preceded by ”999.” Please specify the complete partnumber when ordering. Tools with part numbers beginning with ”J” are available onlyfrom Kent-Moore.

W2002194

9996465 Pressure gauge, 0 –10 bar (0 – 145 psi) 9998338 Connector for checking oil pressure in therocker arm shaft

9812327 Memory cassette 9989876 Dial indicator

9996716 Drift 9998339 Pressure gauge, 0 – 6 bar (0 – 90 psi)

9996956 Cranking tool for flywheel 9998342 Temperature sensors for measuring ex-haust gas temperature

9998190 Measuring instrument 9998344 Drift, used when changing ball seating inthe rocker arm

9998333 Union, used together with pressure gauge9996465

9998364 Collation unit for temperature measuring

9808001 Bolt 9999696 Magnetic base

5

Group 25 Tools

W2003381

1 J-38500–1 Pro-Link® 9000

2 J-38500–1000 Cartridge

3 J-38500–60A Adapter

4 9510060 Multimeter

Other special equipmentTools with part numbers beginning with the letter “J” are available from your local KentMoore dealer.

W2002195

J-35616-20 Jumper wires 9999708 Torque wrench 0 – 17.5 Nm (0 – 15 ft-lb)

J-42472 2-pin breakout harness J- 39200 Fluke 87 digital multimeter

1159794 Torque wrench 10 – 100 Nm(7.5 – 75 ft-lb)

J- 41132 36-pin breakout box

6

Group 25 Design and Function

Design and FunctionEngine Brake

W2000702

1 Camshaft2 Shutter

3 Exhaust Pressure Governor4 Rocker arm

5 Control valve6 Oil pipe

The Volvo Engine Brake consists of two different sys-tems, the exhaust brake and the compression brake.In the VEB, both systems operate at the same time.

Exhaust BrakeThe exhaust pressure governor includes a shutter,mounted in the exhaust side of the turbocharger. Thisshutter, which is connected to the exhaust pressure gov-ernor plunger, restricts the exhaust gas flow whenactivated. Braking is achieved during the exhaust strokeby the backpressure created when the exhaust gas flowis blocked.

Compression BrakeThe compression brake controls the opening of exhaustvalves during the engine compression and combustion(operating) stroke. This creates backpressure in thecombustion chamber which, in turn, has a braking effect.

On engines with compression brakes, the camshaft hastwo extra lobes on each exhaust cam profile. The liftheight of the extra lobes is very low compared to that ofnormal exhaust lobes. To enable the extra lobes to openthe exhaust valves, the exhaust rocker arms are ar-ranged in a manner which reduces valve clearanceduring the braking sequence.

7


Control Valve (VEB)

T2007789

Fig. 1: Engine in operation, the control valve solenoid valve not activated

T2007788

Fig. 2: VEB engine braking, the control valve solenoid valve activated

8


The control valve is mounted on the cylinder head underthe valve cover and is connected to the oil system aheadof the rocker arm shaft. Its purpose is to reduce oil pres-sure to the rocker arms while the engine is operating.There is always full system oil pressure to the controlvalve inlet (1). A pipe connects the inlet to the lube oilgallery in the cylinder block. Oil pressure to the rockerarm shaft can be increased by a solenoid valve (2)mounted on the control valve, from about 100 kPa (14.5psi) while the engine is operating to over 200 kPa (29psi) during compression braking.

During engine operation, the springs’ force and oil pres-sure in the oil chamber hold the control valve plunger inbalance. This action reduces oil pressure.

When the solenoid valve is activated, the oil chamber (6)is drained and the spring (4) presses the plunger (3) toits end position. The plunger completely opens the oiloutlet (5) and the oil pressure to the rocker arm shaft isincreased.

T2006835

Fig. 3: Control valve

1 Oil inlet2 Solenoid valve3 Plunger4 Spring5 Oil outlet6 Oil chamber

Camshaft (VEB)On engines with a compression brake, the camshaft hasan induction lobe (1) and decompression lobe (2) in ad-dition to the normal exhaust lobe (3) on each cam profilefor the exhaust valves. The induction and decompressionlobe lift height is 0.8 mm (0.032 in.) above the basic cir-cle, which is equivalent to about 1.1 mm (0.043 in.) atthe valve bridge. The induction lobe is positioned toopen the exhaust valves at the end of the intake strokeand hold them open at the beginning of the compressionstroke. The decompression lobe is positioned to openthe exhaust valves at the end of the compression stroke.

The valve clearance must be zero for the induction anddecompression lobes to open the exhaust valves.

T2006826

Fig. 4: Camshaft section

1 Induction lobe2 Decompression lobe3 Exhaust lobe

9


Exhaust Rocker Arms (VEB)The exhaust rocker arms on an engine with a compres-sion brake are larger than those of a conventionalengine.

The rocker arm is equipped with a non-return valve anda plunger with a pressure-limiting valve. Its purpose is toregulate oil flow during compression braking.

Spring-tab pressure holds the rocker arm at the rest po-sition against the valve bridge.

Valve clearance is greater on an engine without a com-pression brake, as the induction and decompressionlobes must not open the exhaust valves while the engineis operating.

Shims are placed on the valve bridge to adjust valves.

Note: Do not use more than two shims to obtain propervalve clearance.

T2006827

Fig. 5: Exhaust rocker arm

1 Spring tab2 Non-return valve3 Rocker arm plunger4 Shims

Non-Return Valve (VEB)There is a non-return valve, consisting of a plunger (1),spring (2) and ball (3) in the rocker arm. When oil fromthe rocker arm shaft is forced into the valve, the springforce and the oil pressure determine movement of theplunger.

When the oil pressure is low, about 100 kPa (14.5 psi),the control valve is in its engine operating position. Dur-ing this time, the plunger (1) will not move out of its restposition because the oil pressure cannot overcome thespring force. The plunger pin prevents the ball (3) fromseating and the oil can flow freely through the valve inboth directions.

When the control valve takes up the position for com-pression braking, oil pressure to the non-return valveincreases. The spring force in the non-return valve issuch that when the oil pressure exceeds about 200 kPa(29 psi), it overcomes the spring force and moves theplunger (1) to where it no longer controls the ball (3).The spring (5) forces the ball against its seat and the oilcontained above the plunger (4) cannot flow past the ball(3). As a result, high oil pressure is formed above theplunger (4).

W2000704

Fig. 6: Non-return valve during engine operation

T2006834

Fig. 7: Non-return valve during VEB operation

1 Plunger2 Spring3 Ball4 Rocker arm plunger5 Spring

10


Rocker Arm PlungerThe purpose of the plunger is to zero-set the valve clear-ance during compression braking.

Engine OperationWhen the engine is operating, there is reduced oil pres-sure through the control valve to the rocker arm shaft,and the rocker arm non-return valve (1) is open. Oil canflow freely through the non-return valve in both direc-tions. Therefore, no oil pressure is built up between therocker arm plunger (2) and the rocker arm.

The set valve clearances are great enough to preventthe cam shaft induction and decompression lobes fromopening the exhaust valves.

The valve mechanism operates as it would on an enginewithout a compression brake. That is, only the exhaustlobe opens the exhaust valves.

T2006828

Fig. 8: Rocker arm plunger during engine operation

1 Non-return valve2 Rocker arm plunger

Compression BrakingDuring compression braking, an oil pressure of at least200 kPa (29 psi) is delivered to the rocker arm shaft asthe control valve does not reduce the oil pressure.

The pressure in the rocker arm non-return valve (1) in-creases enough to move the plunger in the non-returnvalve from its rest position, and the ball now functions asa non-return valve. Pressure builds up between therocker arm plunger (2) and the rocker arm. The plungermoves out and forces the rocker arm roller against thelobes on the camshaft. The valve clearance is eliminatedand the lift height on the induction and decompressionlobes is sufficient to open the exhaust valves. The rockerarm plunger is equipped with a pressure-limiting valve(3). When oil pressure between the rocker arm plungerand the rocker arm becomes too high, the pressure-limiting valve opens and oil can exit through the hole inthe bottom of the plunger. The opening pressure of thepressure-limiting valve is governed by the force of thevalve spring.

T2006836

Fig. 9: Rocker arm plunger during compression braking

1 Non-return valve2 Rocker arm plunger3 Pressure-limiting valve

11


Engine Braking

Control System, D12 and D12 AWith the complete release of the accelerator pedal, theengine brake is activated according to the selection madeon the dash board, but only if certain conditions are met:

• Accelerator pedal must be fully released (fuel injec-tion must not occur).

• Engine speed must be greater than 1100 rpm.

• Clutch pedal must not be depressed.

• Boost pressure must be lower than 150 kPa (22 psi).

• Constant engine speed mode (PTO) must not beactivated.

• Engine brake disabled, input must not be activated(ABS).

• Vehicle speed must be greater than 3.2 km/h (2mph).

• Engine temperature must be higher than the follow-ing:

Part number of Tempera-ture Switch

Temperature measured atoutlet of cooling pump

p/n 8155799 43�C (110�F)

p/n 3985349 67�C (158�F)

As an additional option, the engine brake may be en-abled automatically if the vehicle exceeds a specifiedcruise control limit. If this option is selected, the enginebrake may be applied at a selectable speed from 6.4 to32 km/h (4 to 20 mph) above the cruise control setspeed.

W2000877

Fig. 10: Engine brake logic schematic, D12 and D12 A.

12


SwitchesOn the dash the switches for the engine brake have dif-ferent configurations. With the two dual-positionswitches, the brake system is activated by placing one ofthe switches in ON position. The HI/LO switch, in the HIposition, selects both the exhaust brake and the com-pression brake (Volvo engine brake or VEB). In the LOposition, only the exhaust brake is selected.

W3002827

Fig. 11: Dual-position switches for Engine brake

The engine brake switches are on some truck models re-placed by a single three-position switch. As with theswitches above it also regulates the engine brake for thecruise control.

The three position switch has the following selection:

1 No engine brake engaged2 Exhaust brake, EPG3 Exhaust brake and compression brake

T2006953

Fig. 12: Three-position switch for engine brake

Exhaust BrakeDuring exhaust braking, control pressure of about 752kPa (109 psi) activates the exhaust pressure governor.The exhaust pressure governor plunger is activated andthe shutter connected to the plunger restricts the flow ofexhaust gases out of the cylinders.

Restricting the flow of exhaust gases creates a backpressure between the shutter and the piston crowns.This provides a braking effect on the pistons as the ex-haust valves open.

The higher the engine speed during exhaust braking, thegreater the braking effect.

T2006832

Fig. 13: Exhaust pressure governor

13


Compression BrakeThe exhaust brake is always engaged with the com-pression brake. This is because the compression brakeinduction phase fully utilizes the backpressure createdby the exhaust brake in the exhaust manifold.

Induction PhaseThe induction phase begins at the end of the intakestroke and continues slightly into the compression stroke.

The piston travels downward toward bottom dead centerand the camshaft induction lobe opens the exhaustvalves long enough to fill the cylinder with the backpres-sure created by the exhaust brake in the exhaustmanifold.

When the induction lobe closes the exhaust valves, thecylinder has a backpressure at the start of the compres-sion stroke. This backpressure increases compressionconsiderably during the compression stroke which, inturn, creates a powerful braking effect when the pistonmoves upward.

T2006830

Fig. 14: Induction phase

Decompression pPhaseAt the end of the compression stroke, as the piston ap-proaches top dead center, the camshaft decompressionlobe opens the exhaust valves and releases the pressurefrom the cylinder. Shortly before bottom dead center, theordinary exhaust lobe opens the exhaust valves. Duringthe exhaust stroke, a backpressure is created in the ex-haust manifold. This has a braking effect because theexhaust pressure governor shutter is closed.

T2006831

Fig. 15: Decompression phase

14

Group 25 Troubleshooting

TroubleshootingEngine Brake, Fault Tracing

Before working on a vehicle, set the parking brakes,place the transmission in neutral, and block thewheels. Failure to do so can result in unexpected ve-hicle movement and can cause serious personalinjury or death.

When operating a vehicle on streets and highways,during data collection procedure, it is mandatory tohave a second person drive while a technician col-lects the data.

Never disconnect an air system component unless allsystem pressure has been depleted. Failure to de-plete system pressure before disconnecting hoses orcomponents may result in their violent separation andcan cause serious bodily injury.

WARNING

HOT ENGINE! Keep yourself and your test equipmentclear of all moving or hot engine parts. A hot enginecan cause serious burns or can permanently damagetest equipment.

WARNING

Always wear appropriate eye protection to prevent therisk of eye injury due to contact with engine debris orfluids.

CAUTION

Always clean the engine before servicing and keepthe compression brake components clean during allservice and repair procedures. Lack of cleanlinessduring service and repair work could result in a faultor malfunction of the compression brake system.

Basic knowledge of the system description and operationis necessary to perform the troubleshooting proceduresin this manual. For basic system knowledge, refer to:

ServiceManuals

V776–200–820SMSpecifications, VE D12284–610, PV776–TSP128229Engine Control System, VE D12

VEB Diagnosis and Troubleshoot-ingThe D12 engine is equipped with a diagnostic system tosimplify troubleshooting.

The first step to take with all troubleshooting should beto check whether the diagnostic system indicates anyfault codes.

If fault codes are present, these should be corrected be-fore proceeding further with the troubleshooting, even ifthe fault codes do not indicate a fault that would affectthe engine brake system.

If the truck is equipped with ABS, verify that informationcode 61 is not displayed during the check.

For details about how the fault codes and informationcodes are interpreted, refer to:

ServiceManual

280–600, PV776–TSP105620/1Fault Codes, Engine Electronic ControlUnit

15


Electrical Troubleshooting

W2002196

Special tools: J–41132

Connecting test equipment1 Make sure that the ignition key is in the ”OFF” posi-

tion.

2 Clean the area around the EECU and harness con-nectors.

3 Disconnect the EB harness (lower harness). Inspectthe harness for corrosion and damage to the con-nector housing, terminals, and seal. Repair asrequired.

4 Connect the 36–pin breakout box to the EB harnessonly.Make sure the harness connectors are properlypressed together. Do not force connectors together.

Note: Do not connect the breakout box to theEECU.

16


Voltage measurementConditions:

• Engine running

• Engine brake switch in the ON position

• Selector switch in the HI position

• Throttle pedal in idle position

• Clutch pedal released

• ABS not activated

• PTO not activated

• Vehicle speed greater than 3.2 km/h (2 mph)

• Sufficient coolant temperature, see table page 12.

Voltage Measurement 36-Pin Box Selection Intended Value Probable Cause

Engine brake supply (if allconditions are met)

2:9 B+

Faulty connection

Faulty engine brakeswitches

Faulty harness

Resistance measurementConditions for Resistance Measurements:

• Ignition off

• Engine not running

• Engine brake switch in the ON position

Note: Values in table apply to solenoid valve withpart no 1610563 and 1610567.For solenoid valves with part numbers 8143014 and8143018, please refer to:

ServiceManual

PV776–280–600SMElectronic Controls, VE D12, D12 A,D12 B

Resistance Measurement 36-Pin Box Se-lection

IntendedValue Probable Cause

Solenoid valve, exhaust brake (enginebrake selector switch in LOW position

2:9 13 – 16

Faulty connection

Faulty harness

Solenoid valve (exhaust brake)

Faulty exhaust brake

Faulty engine brake switches

Solenoid valve exhaust brake andcompression brake (engine brake se-lector in HI position)

2:9 7.5 – 9.5

Faulty connection

Faulty harness

Solenoid valve (compression brake)

Faulty engine brake switches

Faulty VEB coolant temperature switch

Note: If the multimeter shows 20–22 when the enginebrake select switch is in the HI position, the exhaustbrake solenoid valve is damaged.

17


Mechanical Troubleshooting

Conditions• The electrical troubleshooting has been carried out,

or any possible faults in the electrical system can becompletely eliminated.

• The truck has full pressure [827 kPa (120 psi)] inthe air system.

• The engine has normal oil pressure.• The engine coolant temperature is at operating tem-

perature.

Service procedures not contained in this informa-tion are to be found in the service information forthe VOLVO D12 engine under the respective group.

Exhaust brake Compression brake

Test 1 Test 1

Test 2 Test 3 Test 2

Test 4 Test 5

Carry out the tests on the exhaust brake and com-pression brake in numerical order according to theabove diagram, when either one of the brake sys-tems does not work.

If both brake systems work, but give poor braking ef-fect, see “Low Engine Braking Effect (VEB)” page 21.

18


VEB Troubleshooting, Order toFollowIf the fault remains after correcting any indicated faultcodes, and the engine and electrical system functionnormally, troubleshooting should be performed in the fol-lowing order:

1Begin troubleshooting by attempting to establish which ofthe brake systems is faulty (exhaust brake, compressionbrake, or both systems).

2Verify that the following preconditions for exhaust brak-ing are satisfied, with the switch(es) on the instrumentpanel in the ON/LOW (exhaust brake only) positions.

• Accelerator pedal position at 0% (idle position)• Clutch pedal not depressed• Engine speed should be greater than 1100 RPM• PTO not activated• Vehicle speed should be greater than

3 km/h (2 mph).• Anti-lock Braking System (ABS) not activated.• Boost pressure less than 150 kPa (22 psi).

Note: The exhaust brake will engage only when all ofthese preconditions are satisfied.

Note: When the exhaust pressure governor (EPG) is ac-tivated in conjunction with starting, running the enginewarm, and keeping the engine warm, other preconditionsapply.

3Verify that the following preconditions for VEB (exhaustbraking and compression braking) are satisfied, withthe switches on the instrument panel in the ON/HI (ex-haust brake and compression brake, VEB) positions.

• Accelerator pedal position at 0% (idle position)• Clutch pedal not depressed• Engine speed should be over 1100 RPM• PTO not activated• Vehicle speed should be greater than 3 km/h

(2 mph).• Anti-lock Braking System (ABS) not activated.• The coolant temperature should be over 43 �C

(110�F), otherwise only the exhaust brake will beengaged.

• Boost pressure less than 150 kPa (22 psi).

Note: An additional option is to have the VEB enable au-tomatically if the vehicle exceeds a specified cruisecontrol limit. If this option is selected, the VEB will auto-matically engage at a selectable speed approximately6.4 to 32 km/h (4 to 20 mph) above the set cruise con-trol speed.

4Always begin with electrical troubleshooting, unlessa fault in the electrical system can be completelyruled out.

19


VEB Fault Symptoms

Fault symptom 1The engine will not start

Probable fault:

• The control valve plunger may be stuck in its restposition. If this is the case, oil is fed to the rockerarm shaft with full pressure and the plungers in therocker arm shafts will be pressed out. This will elimi-nate the valve clearance and the decompressionlobes will open the exhaust valves. This impairs thecompression build-up and the engine cannot start.

Carry out mechanical troubleshooting.

Fault symptom 2Neither the exhaust brake nor the compressionbrake functions

This indicates a fault in the electrical system. The controlsignal is not reaching the exhaust pressure governor andthe control valve solenoid valves.

Carry out electrical troubleshooting.

Fault symptom 3The exhaust brake functions, but not the compres-sion brake

Probable fault:

• No control signal to the compression brake controlvalve

• Defective temperature sensor or diode• Defective control valve or control valve plunger stuck• No ground at coolant temperature switch• Drain channel is clogged


If the fault remains:Carry out mechanical troubleshooting.

Fault symptom 4The compression brake functions, but not the ex-haust brake

Probable fault:

• No or low air pressure supplied to the EPG• No control signal to the exhaust pressure governor

solenoid valve• Defective solenoid valve• Defective exhaust pressure governor• Defective quick-release valve• Air leakage


If the fault remains:Carry out mechanical troubleshooting.

Fault symptom 5Poor braking effect from the exhaust brake

Probable fault:

• Low control pressure supplied to the EPG• Leaks in the exhaust manifold gaskets• Exhaust pressure governor seizing• Defective or leaking exhaust pressure governor


Fault symptom 6Poor braking effect from the engine brake (exhaustbrake and compression brake)

Probable fault:

• Low control pressure supplied to the EPG• The control valve gives too low oil pressure• Defective non-return valve in one or more of the

rocker arms• Defective pressure limiting valve in one or more of

the rocker arm plungers• The exhaust brake functions poorly or not at all• Exhaust valve clearance is too large

See the procedures in “Low Engine Braking Effect(VEB)” page 21.

Fault symptom 7The compression brake engages but will not disen-gage

If the compression brake remains engaged with full ef-fect even though the accelerator pedal is depressed, thisis due to the control valve plunger remaining in the”VEBposition”and directing full system oil pressure out to therocker arms.

Do not depress the clutch pedal unless necessary.Engine may stop if compression brake stays engaged.This will result in loss of power steering assistance.

If the compression brake only partly disengages, it ismost probable that one of the rocker arm plungers haslocked in its outer position. With this fault, the engineruns unevenly due to low compression pressure in thecylinder where the rocker arm plunger has stuck.

The fault generates one of the fault codes 31–36, as thecontrol unit compensates for the loss of power in thecylinder by increasing the amount of fuel delivered to thecylinder through the unit injector. When the maximumamount of fuel delivered by the unit injector can not com-pensate for the loss of power in the cylinder, the faultcode is generated.


Note: Fault codes 31–36 can also be generated by anelectrical fault in the fuel system.

20


Low Engine Braking Effect (VEB)Note: Before carrying out the following procedure, readthe troubleshooting general information in “Engine Brake,Fault Tracing” page 15.

Check Before the Test:• That the conditions for exhaust braking and com-

pression braking are satisfied.• That the general condition of the engine is good.• That the engine has normal oil pressure.• That both the engine brake systems are functioning.

Check that both the exhaust brake and engine brake arefunctioning by test-driving the truck.

• Set the engine brake switch to OFF.

• Drive the truck downhill, fully release the acceleratorpedal and set the switches to ON/LOW positions.If the engine sound does not alter and/or there is nobraking effect, the exhaust brake does not function.If the engine sound changes and there is a notice-able braking effect, the exhaust brake does function.Set the switches to ON/HI positions.

• If no difference can be noted in the sound or in thebraking effect, the compression brake does notfunction.

• If the engine sound changes and there is a notice-able braking effect, the compression brake doesfunction.

Check that the valve clearances are within the tolerancerange.

Test Equipment, Installation1Install the equipment for measuring the oil pressure inthe rocker arm shaft according to the instructions in “OilPressure, Compression Brake, Checking” page 36.

2Set the control switches to the OFF position (VEB dis-abled). Start the engine and measure the rocker armshaft oil pressure. The pressure should be approximately1 bar (14.5 psi).

If the pressure fluctuates or is under 0.5 bar (7.25 psi) orover 1.5 bar (21.75 psi), the control valve is faulty.

Note: Low oil pressure in the rocker arm shaft may alsobe due to excessive wear in the rocker arm bushings and/or the rocker arms which result in excessive oil pressureloss. See “Rocker Arm Roller, Checking” page 46.

3Install the equipment for measuring the exhaust gastemperature, including the 36-pin breakout box. See“Exhaust Temperature, Checking” page 40.

Test-driving and MeasuringTo obtain good test results, the exhaust pressure gover-nor should be disabled when checking the function ofthe compression brake.

• Route the 36-pin breakout box into the cab and se-cure.

• Make sure the engine brake switch is OFF.

• Bridge terminals 2 and 11 of the 36-pin breakoutbox.

When terminals 2 and 11 of the 36-pin breakout boxare bridged, the compression brake will activate any-time the VEB control switch is in the ON position,regardless of status. The compression brake will re-main ON until the control switch is moved to the OFFposition. While the engine brake is activated, do notdepress the accelerator or clutch. If the accelerator isdepressed, engine damage may result. If the clutch isdepressed a loss of power steering assist may occur.Be prepared to switch off the engine brake at any time.Failure to do so may result in personal injury or death.

When operating a vehicle on streets and highways,during data collection procedure, it is mandatory tohave a second person drive while a technician col-lects the data.

When engine braking, the exhaust gas temperature in-creases on those cylinders where the compression brakefunctions.

On the cylinder(s) where there is little or no braking ef-fect there is very little exhaust gas temperature increase,thus, the cylinder which gives a very low or no brakingeffect can be identified.

Note: The temperature difference between cylinders isnot important when performing this test. Only note thedifference in temperature at the beginning and end of theengine braking function on each individual cylinder.

For the measurement to be valid, select gears, speedand section of road where the braking procedures canbe carried out continuously and without interruption.

Select a long, at least 1.2 mile (2 km), downhill sectionof road, where the engine braking procedures can becarried out without reducing the speed of the truck.

The truck should be loaded and the road conditionsclear.

Make sure that the engine brake switch(es) on the in-strument panel are in the OFF position, until ready toperform the test at the test location.

21


Voltage supply to the measuring instrument is providedby the cigarette lighter socket and the purpose of the in-strument back-up mode is to prevent stored informationbeing lost if the external voltage supply is temporarilybroken.

When the external voltage supply is broken, the displaylighting goes out and the text begins to flash. If this oc-curs during measuring, the stored values are retainedand the measurement procedure can continue when theinstrument voltage supply is restored.

The instrument can store 10 measurement values.The first measurement value is stored as value A, thesecond measurement value is stored as value B, thethird as value C etc.The instrument can also calculate the difference betweentwo measurement values, for example B – A, D – C, etc.

Note: It is not possible to carry out measurements orstore measurement values when the instrument is in theback-up mode.

Brake Test1

T2008010

Check that the measurement instrument display showsthe text Temperature.

2

T2008011

Press * once.The display should now show the text Temp. Display.

3

T2008019

Press * one more time.The display should now show six temperature values,one for each cylinder, with no. 1 cylinder shown on theextreme left of the display.The instrument will now measure temperature continu-ously.

4

Accelerate the truck and select a gear that enables youto hold a stable engine speed of approximately 1400RPM when the accelerator pedal is completely released(idle position).(Use the service brakes as an aid in holding a stable en-gine speed, as this procedure is to be performed withthe engine brake OFF.)

22


5

T2008012

• Completely release the accelerator pedal (idle posi-tion).

• While viewing the measurement instrument, wait forthe exhaust gas temperature to drop and begin tostabilize.

• Press * once.

The measurement value designation A is shown forapproximately 1 second on the display and is a confir-mation that the value is registered and stored.

The measurement instrument then returns automaticallyto continuous measurement and shows six measure-ment values, one for each cylinder.

6


Set the engine brake switches to ON/HI. Read the rockerarm shaft oil pressure on the pressure gauge when thepressure has stabilized.Note the value.

7

T2008013

• View the measurement instrument, wait for the tem-perature to rise and begin to stabilize.

• Press * once.

The measurement value designation B is shown forapproximately 1 second on the display and is a confir-mation that the value is registered and stored.

The measurement instrument then returns automaticallyto continuous measurement.

Carry out the brake test and measurements at leastthree times to obtain a valid result.

Note: Remember the engine brake will remain active un-til switched OFF.

Store the measurement values by pressing *.

The instrument can store 10 measurement values (theresults from 5 measurements of Low / High tempera-tures per cylinder).

23


8

T2008011

When a sufficient number of measurements have beencarried out, set the engine brake switch(es) to the OFFposition and remove the bridge between terminals 2 and11 at the 36-pin connector.

Hold * pressed in (approximately 2 seconds) until thetext Temp. Display is shown on the display.

9

T2008014

Press until the text Temp. Evaluation is shown onthe display.

10

T2008021

Press * and the first stored measurement value is dis-played. The identification letter A appears before themeasurement value.

By pressing or it is possible to view all thevalues on the display.

By pressing * again, the measurement value stored af-ter the letter B is displayed.

24


11

T2008022

By pressing * again, the difference between measure-ment values B and A is shown.

By pressing or it is possible to view all thevalues on the display.

Note: If the first measurement value is greater than thesecond, the difference between the values will be shownas a minus value on the display.

12

T2008020

Press * once.

The first stored value from the second measurement(value C) is shown on the display.

By pressing * one more time, the measurement valuestored after the letter D is displayed.

By pressing * again, the difference between measure-ment values D and C is shown.

13

The results from the third, and if necessary, the fourthand fifth measurements are produced in the same wayas with measurements one and two.

By pressing *, it is possible to move between 10 mea-surement values and 5 differences.

14

Note the measurement results and remember that a fullycharged back-up battery retains the stored measurementvalues in the instrument for max. 20 minutes after theexternal voltage supply has been broken. If possible, donot break the voltage supply to the instrument before allthe measurement results have been noted.

15

T2008015

Hold * pressed in (approx. 2 seconds), when all mea-surement results have been noted, until the text Temp.Evaluation is shown on the display.

16

T2008023

Press until the display shows the text Temp. Dis-play.

25


17

T2008024

By holding * pressed in for approximately 2 secondsuntil the display shows the text Temperature, the instru-ment leaves the back-up mode and all the storedmeasurement values are cleared.

Note: Make sure that the values are noted beforethe instrument is set in position Temperature.

18

Disconnect the electrical plug for the external voltagesupply.

Note: Switch the instrument off by holding * pressed infor approx. 2 seconds when the display shows the textTemp. Evaluation or Temp. Display, after the externalsupply contact has been broken.

Do not leave the instrument in battery back-up mode.The battery will discharge very quickly if the externalvoltage supply is broken and the instrument has to relyon battery back-up.

19

Evaluate the test.

Evaluation of the Brake TestWhen the switch(es) are moved from position OFF to po-sitions ON/HI, the oil pressure in the rocker arm shaftshould rise to min. 2 bar (29 psi).If the oil pressure does not exceed 2 bar (29 psi), thecontrol valve is faulty.

Note: Low oil pressure in the rocker arm shaft may alsobe due to excessive wear in the rocker arm bushingand/or rocker arms which result in excessive oil pressureloss. See “Rocker Arm Roller, Checking” page 46.

The temperature increase for each individual cylindershould be between 90�C and 130�C (194�F and 266�F)in order to be certain that the compression brake oneach cylinder is functioning properly.

If there is no temperature increase, or if the temperatureincrease is less than 80�C (176�F) on any individualcylinder, the compression brake on that cylinder is notfunctioning properly.

If the result of a test is not clear, the test must berepeated. At least three tests should be carried out in or-der to obtain valid results.

The measured exhaust gas temperature varies betweenthe cylinders, depending on the position of the cylinders.

The cylinders that are positioned nearest the tur-bocharger will have a higher measured value than thoseat either end of the cylinder block. This is due to thetemperature sensors also being influenced by the pass-ing air flow from the cylinders furthest away from theexhaust manifold outlet.

When evaluating the test, this point should also be takeninto consideration.

For example, when comparing cylinders 1 and 6, thetemperature increase should more or less be the same,providing that the compression brake is functioning prop-erly on both cylinders.

The same comparison can be made between cylinders 2and 5 and cylinders 3 and 4.

It should be pointed out that it requires repeated braketesting to be able to obtain an indication that the brakingeffect on a cylinder is reduced.

In instances where there is no braking effect on a cylin-der, there is also no reference to compare an equivalentcylinder with.

The less the braking effect is reduced on a cylinder, thegreater the difficulty in identifying the cylinder.

26


2531-06-02-01Engine Brake, Checking


WARNING


Note: Before carrying out the following procedure, readthe troubleshooting general information in “Engine Brake,Fault Tracing” page 15.Special tools: J–39200 Fluke 87 Multimeter

Measurement 1

1

W2002218

Move the switch(es) on the instrumentpanel to ON/HI (exhaust brake andcompression brake, VEB) positions.

2Bridge terminals 3 and 10 on thebreakout box. Doing so energizes theEECU power supply relay by providinga ground to the coil side of the relay.

3Set Multimeter to measure Amps andconnect it to terminals 2 and 11 on the36–pin breakout box. This suppliesbattery voltage and measures currentdraw to the brake circuit (exhaustbrake only).

4An audible ”click” should be heardfrom the exhaust brake solenoid valvewhen the multimeter is connected.

5If no ”click” is heard from the exhaustbrake solenoid valve, and the exhaustbrake measurement 1 results wereOK, replace the HI/LO switch. Other-wise, proceed to step 6.

6Disconnect the connector on the ex-haust brake solenoid valve.

7Bridge terminals 3 and 10 on thebreakout box.

8Set Multimeter to measure Amps andconnect it to terminals 2 and 11 on the36–pin breakout box.

9A faint ”click” should be heard from thecompression brake solenoid valvewhen the multimeter is connected.

Note: Coolant temperature should beabove 43�C (110�F), otherwise VEBcoolant switch must have a jumperwire installed.

10The multimeter should show 0.525Amp.

11If no ”click” is heard from the compres-sion brake solenoid valve, or if themultimeter does not show the value0.525 Amp, carry out Measurement 2.

27


Measurement 2

1Bridge terminals 2 and 11 on the 36–pin breakout box.

2Disconnect the 2-pin connector at theexhaust brake solenoid valve and con-nect the J–42472 breakout harnessbetween the solenoid valve and thewiring harness.

3Set multimeter to measure Voltageand connect it to pins 1 and 2 on thecompression brake connector at theupper timing gear cover.Intended value: B+

4If the intended value is correct, re-move the valve cover and carry outMeasurement 3.

5If the intended value is not correct,carry out Measurement 4.

Measurement 3

1Set multimeter to measure Ohm ().

2Measure between 1 and 2 on the com-pression brake solenoid valve.Intended value: 20± 2

3If the intended value is correct, checkthe cables between the compressionbrake solenoid valve and the connec-tor at the upper timing gear cover.

4If the intended value is not correct, re-place the compression brake solenoidvalve.

Measurement 4

1Set Multimeter to measure Voltage.

2Measure between alternate groundand pin 1 in the connector for the con-trol valve solenoid valve at the uppertiming gear cover.Intended value: B+

3If the value is not correct, check thewire to pin 1 in the connector for thecontrol valve at the upper timing gearcover and to pin 2 at the EB connectorincluding the engine brake switch(es).Make repairs and retest.

4If the value is correct, measure be-tween alternate battery supply and pin2 in the connector for the control valvesolenoid at the upper timing gearcover.Intended value: B+

5If the value is correct, clean and in-spect both pins and sockets at theconnector for the control valve sole-noid. Repeat measurement 1.

6If the value is not correct, check thewire from pin 2 in the connector for thecontrol valve at the upper timing gearcover to its ground location, includingcompression brake coolant tempera-ture switch.

28


2533-06-02-01Solenoid Valve, CompressionBrake, Checking



WARNING


WARNING


Note: Before carrying out the following procedure, readthe troubleshooting general information in “Engine Brake,Fault Tracing” page 15.Special tools: 9998338, 9998339

Test 1

1

T2007704

Remove the valve cover and checkthat the plugs in the front and rear endof the rocker arm shaft are in position.

2

T2007740

Remove the control solenoid valve andcheck that the drain holes in the sole-noid valve are not clogged.

3Check that the drain channel in thecontrol valve is not clogged.

4Check that the valve clearances arewithin tolerance.

29


Test 2

1

W2002231

Install the equipment for measuringthe oil pressure in the rocker arm shaftaccording to the instructions in “OilPressure, Compression Brake, Check-ing” page 36.

2Test-drive the vehicle and allow it toreach operating temperature.

3Activate the engine brake by makingsure the switch(es) on the instrumentpanel are in the ON/HI position andthe conditions for engine braking aresatisfied.

4When the oil pressure has stabilizedrecord the gauge reading during en-gine brake operation.The pressure should be at least 2 bar(29 psi).

5Repeat the test a number of times toconfirm the measurement reading.

6Replace the control valve if the mea-sured pressure is below 2 bar (29 psi)and the rocker arms, nozzles for lubri-cating the ball sockets, bushings andother components on the rocker armbridge are not damaged.

2531-06-02-02Exhaust Brake, ElectronicCheckingNote: Before carrying out the following procedure, readthe troubleshooting general information in “Engine Brake,Fault Tracing” page 15.Special tools: J–3920 Fluke 87 Multimeter

W2002218

Measurement 1

1Move the switch(es) on the instrumentpanel to ON/LOW (exhaust brake only)positions.

2Bridge terminals 3 and 10 on thebreakout box. Doing so energizes theEECU power supply relay by providinga ground to the coil side of the relay.

3Set Multimeter to measure Amps andconnect it to terminals 2 and 11 on the36–pin breakout box. This suppliesbattery voltage and measures currentdraw to the brake circuit (exhaustbrake only).

4An audible ”click” should be heardfrom the exhaust brake solenoid valvewhen the multimeter is connected.

5The multimeter should show 0.7 ± 0.1Amp.

30


6If no ”click” is heard from the exhaustbrake solenoid valve, or if the multime-ter does not show the value 0.7 ± 0.1Amp, proceed to the next measure-ment.

Measurement 2

1Bridge terminals 2 and 11 on the 36–pin breakout box in addition to theconnections in measurement 1.

2Disconnect the 2-pin connector at theexhaust brake solenoid valve and con-nect the J–42472 breakout harnessbetween the solenoid valve and thewiring harness.

3Set multimeter to measure Voltage.Measure between pins 1 and 2 on thebreakout harness. Intended value: B+(battery positive voltage ~12V).

4If the intended value is correct, replacethe exhaust brake solenoid valve.

5If the intended value is not correct,carry out Measurement 3.

Measurement 3

1Set multimeter to measure Voltage.

2Measure between alternate groundand pin 1 in the breakout harness.

Intended value: B+

3If the intended value is correct, checkthe cable from pin 2 in the connectorfor the exhaust brake solenoid valve toground.

4If the intended value is not correct,check the wire between pin 1 in theconnector for the exhaust brake sole-noid valve and pin 2 at connector EB,including the engine brake switch(es).

Measurement 4

1Note: A functional diode allows cur-rent to flow in one direction only.Connect the J-42472 2-pin breakoutharness to the exhaust brake solenoidonly.

Note: Do not connect to the engineharness.

2Select the diode test on the Fluke 87or equivalent multimeter.

3Touch the red probe to the positiveside of the diode (pin 1 of the J-42472breakout harness) and the black probeto the negative side of the diode (pin 2of the breakout harness).

4If the diode is good, the voltage dropshould typically be 0.5 V to 0.8 V.

5Reverse the probes and measure thevoltage across the diode again. If thediode is good, the display will showOL (overload).

6If the display shows 0.00 in both direc-tions, the diode is shorted. If thedisplay shows OL in both directions,the diode is open. Replace thesolenoid. See “Solenoid Valve, Com-pression Brake, Replacement” page51.

31


2531-06-02-03Exhaust Brake, MechanicalChecking


WARNING


WARNING


Note: Before carrying out the following procedure, readthe troubleshooting general information in “Engine Brake,Fault Tracing” page 15.Special tools: 9996465, 9998333

Test 1

1

W2002234

1 EPG solenoid (cold mode)2 Exhaust brake solenoid

Verify proper wiring to solenoids. Wire628 to the exhaust brake solenoid andwire 636k to the exhaust pressuregovernor (EPG) solenoid.

2Verify correct air regulator valve isused with the proper system. The ex-haust brake requires the 7.5 barregulator, while the EPG utilizes a 2.3bar regulator.

3

W2002198

VN solenoid location — other vehicles havesolenoids located on bulkhead

Connect the J–42472 2-pin breakoutharness to the exhaust brake solenoidvalve, using 2 jumper wires with“alligator” type ends, supply the sole-noid with an alternate ground and B+and listen to hear if the exhaust pres-sure governor shutter moves.

Note: Make sure that pin 1 of the J–42472 is connected to B+ and pin 2 isconnected to B-.

4

T2007700

If the exhaust pressure governor shut-ter moves, carry out test 3.

32


5

T2007701

If the exhaust pressure governor shut-ter does not move, remove the airhose from the exhaust pressure gover-nor and activate the exhaust brakesolenoid valve again.

6If no air comes out of the hose, carryout Test 2.If air comes out of the hose, carry outTest 3.

Test 2

1Check that the air hoses are nottwisted or blocked.Replace damaged hoses.

2

T2007953

Remove the air hose from the quickrelease valve and activate the exhaustbrake solenoid valve.If air comes from the hose, the quickrelease valve is faulty and should bereplaced.

3If no air comes out of the hose, checkthat air reaches the exhaust brake so-lenoid valve.If air reaches the exhaust brake sole-noid valve, the valve is faulty andshould be replaced.

4If no air reaches the exhaust brake so-lenoid valve, check that air reaches theregulator valve for the exhaust brakesolenoid. If no air reaches the air reg-ulator valve, check or replace the airsupply hose. If air reaches the air reg-ulator valve, then the air regulatorvalve is faulty and should be replaced.

33


Test 3

1

T2007707

Connect the pressure gauge to the ex-haust pressure governor hose andactivate the exhaust brake solenoidvalve.

Note: The pressure in the hose shouldbe 7.5 ± 0.3 bars (109 ± 4.4 psi).

999 6465999 8333

2If the pressure is too high or too low,carry out Test 4.If the pressure is within the tolerances,carry out Test 5.

Test 4

1Check that the hoses are not twistedor blocked.Replace damaged hoses.

999 6465999 8333

2

W2002211

1 EPG solenoid (cold mode)2 Exhaust brake solenoidSolenoids are located on the bulkhead; VN vehicleshave solenoids mounted on the engine

Remove the hose from the exhaustbrake solenoid valve and measure theoutput pressure. The pressure shouldbe 7.5 ± 0.3 bars (109 ± 4.4 psi).

Never disconnect an air system component unless allsystem pressure has been depleted. Failure to depletesystem pressure before disconnecting hoses or com-ponents may result in their violent separation and cancause serious bodily injury.

3If the pressure is within the tolerances,the quick release valve is faulty andshould be replaced.

34


4

W2002212

If the pressure is too high, go to step 4.If the pressure is too low, go to step 5.

Note: Trucks with a higher systempressure than 7.5 bar (109 psi) areequipped with an adjustable reductionvalve to reduce the pressure to the ex-haust pressure governor.

5Adjust the valve setting to specifiedpressure. If pressure will not respondto adjustment, replace regulator. Afteradjustment, the knob on the valveshould be sealed or made tamperproof.

6Check the outlet pressure of the regu-lator going to the exhaust brakesolenoid.Intended value: 752 ± 30 kPa (109 ±4.4 psi)

7Pressure OK:

• Restriction in line from regulatorvalve to exhaust brake solenoid.(VN series)

• Faulty solenoid.

8Pressure not OK:

• Regulator valve out of adjustmentor faulty.

• Insufficient supply pressure.

Test 5

1Remove the exhaust pipe from theshutter housing.

2

W2002189

Measure the opening between theshutter disk and shutter housing (A),to check that the EPG shutter has notjammed in the closed or half-closedposition.The value (measurement A) shouldbe 30 ± 2 mm (1.18 ± .08 in).

3If the value is correct, replace or over-haul the EPG in accordance with theprocedures found in:

ServiceManual

V776–250–600SMIntake and ExhaustSystems, VE D12

4Activate the exhaust brake solenoidvalve.

35


5

T2007703

Check if the exhaust pressure gover-nor shutter seals against the shutterhousing.

6If the shutter does not seal against thehousing, replace or overhaul the ex-haust pressure governor according tothe procedures found in:

ServiceManual

V776–250–600SMIntake and ExhaustSystems, VE D12

7If the shutter seals against the hous-ing, remove the exhaust pressuregovernor and check the shutter andshutter housing.

2533-06-02-02Oil Pressure, CompressionBrake, Checking



WARNING


WARNING


36


(Measured at rocker shaft.)Special tools: 9998338, 9998339, J–41203(Kent Moore)

Installation

1Set the parking brake.

2

T2006731

Remove the valve cover.

Note: With older engines avoiddamage to the valve cover and internalinjector cable harness by making surethe mounting screws do not unscrewfrom the cylinder head during removal.Do not use impact tools to remove thenuts securing the valve cover.

3

T2008279

Remove the bolts retaining the rockerarm bridge between cylinders 4 and 5.Remove the spring washer.

4

T2008278

Reinstall the front bolt without thespring washer. Install bolt 9808001with connector 9998338 into the rearbolt hole and tighten both bolts.

Note: Bolt 9808001 must be used. Ithas been modified and is shorter thanthe previous version and does not usea sleeve.

9998338

5

Remove the valve cover stud locatedbetween no. 4 and 5 injector solenoids.

Note: Use Kent Moore tool J–41203 toremove the stud on earlier D12 en-gines.

J-41203

37


6

W2002199

Route the oil pressure hose throughthe hole in the valve cover where thestud has been removed. Connect theoil pressure hose to connector9998338.

Note: Check that connector 9998338and the oil pressure hose do not ob-struct the rocker arms. If necessary,use cable ties to prevent the oil pres-sure hose from being damaged by therocker arms.

7Install the valve cover and make surethe oil pressure hose does not interferewith any part of the valve mechanism.

8

T2007003

Tighten the valve cover nuts to30 ± 3 Nm (22 ± 2 ft-lb). Follow thetightening sequence shown.

30 ± 3 Nm(22 ± 2 ft-lb)

9

W2002200

Install the seal for the oil pressurehose into the hole in the valve cover.Make sure the seal fits into the studhole in the valve cover.

10

W2002213

Route the oil pressure hose into thecab as shown. Install pressure gauge9998339

Note: Secure the oil hose with cableties to prevent kinks that would restrictflow.

9998339

38


Testing

1Set the control switches to the OFFposition (VEB disabled). Start the en-gine and measure the rocker arm shaftoil pressure. The pressure should beapproximately 1 bar (14.5 psi).

2If the pressure fluctuates or is under0.5 bar (7.25 psi) or over 1.5 bar(21.75 psi), the control valve is faulty.

Note: Low oil pressure in the rockerarm shaft may also be due to exces-sive wear in the rocker arm bushingsand/or the rocker arms which result inexcessive oil pressure loss. See“Rocker Arm Roller, Checking” page46.

3Install the equipment for measuringthe exhaust gas temperature, includingthe 36-pin breakout box. See “ExhaustTemperature, Checking” page 40.

Removal

1Set the parking brake. Remove thepressure gauge and oil pressure hosefrom the cab. Cut the oil hose freefrom the cable ties and disconnect thepressure gauge.

2

T2006731


CAUTION

With older engines avoid damage to the valve coverand internal injector cable harness by making sure themounting screws do not unscrew from the cylinderhead during removal. Do not use impact tools to re-move the nuts securing the valve cover.

3Remove the oil pressure hose fromconnector 9998338. Pull the oil pres-sure hose through the valve cover andremove the oil seal.

4

T2007708

Remove connector 9998338 and bolt9808001 from the rocker arm shaft. In-stall the spring washer and the tworocker arm bridge bolts.

39


5Tighten the rocker arm bridge bolts intwo steps:1 Torque to 15 Nm (11 ft-lb).2 Tighten both bolts an additional

90�.

15 Nm(11 ft-lb)

6Clean the threaded hole in the cylinderhead where the valve cover stud wasremoved. Clean the valve cover studbolt and apply locking fluid. Torque thestud to 48 ± 8 Nm (35 ± 6 ft-lb).

Carefully remove any excess lockingfluid after the stud bolt has been tight-ened.

Note: Use Kent Moore tool J-41203 onearly D12 engines to torque the stud.

J-4120348 ± 8 Nm(35 ± 6 ft-lb)

7Press the electronic cable clamp ontothe stud bolt.

Note: The electronic cable must bepositioned on the outside of the valvecover studs.

8Install the valve cover.

9

T2007003

Tighten the valve cover nuts to30 ± 3 Nm (22 ± 2 ft-lb). Follow thetightening sequence shown.

30 ± 3 Nm(22 ± 2 ft-lb)

10Test run engine and check for oil leaks.

2515-06-02-01Exhaust Temperature, Check-ing


WARNING


WARNING


Special tools: 9998190, 9998342, 9998364,J–41132

Installation


2

W2002214

Disconnect the pipe from the air com-pressor and remove the intake pipebetween the air cleaner and tur-bocharger.

40


3Remove bolts and spacers fasteningthe heat shield to the exhaust mani-fold.

4Disconnect the air compressor dis-charge line and lay aside.

5Unbolt the oil supply line at the turboonly.

6

T2007719

Loosen the exhaust manifold bolts justenough so that some threads remainin the cylinder head.

7

T2008047

Insert the temperature sensors be-tween the exhaust manifold and thecylinder head.Insert the temperature sensors farenough that the guide pins are againstthe edge of the exhaust manifold.

Note: The temperature sensors arenumbered from one to six for the re-spective cylinders.Make sure that the sensors are in-stalled to the correct cylinders.The sensors can be installed on eitherside of the gasket.(The gaskets are replaced after thetest.)

9998342

8Tighten the exhaust manifold bolts.

9Tighten the oil supply line at the turbo.

10Connect the air compressor dischargeline.

11Secure the temperature sensor cableswith cable ties away from the exhaustmanifold and to avoid damage duringtesting.

Route the cables into the cab for con-nection to the measuring instrument.

12Install the intake pipe between the aircleaner and the turbocharger. Connectthe pipe to the air compressor.

41


13Make sure that the ignition key is inthe OFF position.

14Clean the area around the EECU andharness connectors.

15Disconnect the EB harness (lower har-ness) from the EECU and connect the36-pin breakout box between the EBharness and the EECU.

Make sure the harness connectors areproperly pressed together. Do notforce the connectors together.

16Route the 36-pin breakout box into thecab and secure.


17

W2002215

1 EPG solenoid wiring harness2 Exhaust brake solenoid wiring harness

Remove the connector from the ex-haust brake solenoid valve.

Note: A more reliable measurementresult is obtained when the exhaustbrake is disabled.

Measurement instrument 9998190

1

T2008016

Check that the correct program unit isinstalled in measurement instrument9998190.

Note: When temperature measuring,program unit 9812327 is required.

99981909812327

42


2

T2008017

Make sure that a back-up battery is in-stalled in measurement instrument9998190.The back-up function is there to makesure that the stored information is notlost in the event of a temporary loss ofsupply voltage.

With a fully charged battery, the storedvalues in the instrument are retainedfor max. 20 minutes after the externalvoltage supply has been broken. Al-ways make sure that the battery isfully charged when temperature mea-surement is to be carried out.

Note: Only use a 9 Volt rechargeablenickel-cadmium battery in the mea-surement instrument.

Collation unit 8364

1

T2008018

Connect the collation unit to the mea-surement instrument and plug in thenumbered electrical connectors fromthe temperature sensors to the num-bered positions in the collation unitconnection panel.

9998364

2

T2008010

Connect the collation unit electrical ca-ble to the cigarette lighter socket andturn the ignition key to ”ON” position.

Note: Check that the text Tempera-ture is shown on the measurementinstrument display.The measurement instrument auto-matically selects the temperaturemeasurement function when the colla-tion unit is connected.

43


Removal

1Set the parking brake. Take the mea-surement instrument and temperaturesensor electrical cables out of the cab.

2Remove the cable ties and the electri-cal sensor cables.

3Disconnect the pipe from the air com-pressor and remove the intake pipebetween the air cleaner and tur-bocharger.

4Remove the 4 mounting bolts and liftaway the air filter housing.

5Disconnect the oil supply line to the aircompressor at the oil filter housingand remove the line clamp.

Note: Cover the fitting and the end ofthe line to keep out any debris.

6Remove the 2 bolts attaching thelower charge air cooler pipe to theturbo and the bolt supporting the lowerend of the pipe.

7Pry the charge air cooler pipe awayfrom the turbo and remove the endadapter for more clearance.

8Remove the shutter housing turboclamp. Move the shutter housing awayfrom the turbo and let it rest on theframe.

9Blow all debris away from the areawhere the turbocharger oil supply lineenters the oil filter base. Remove the 2bolts fastening the supply line to theturbocharger and remove the line.

Note: Cover the open hole in the oilfilter base to prevent debris fromentering.

CAUTION

In order to prevent personal injury, always wear safetyglasses when working with compressed air.

10Remove the 2 bolts fastening the oildrain back tube to the turbo.

11Remove the 4 bolts mounting theturbo to the exhaust manifold and liftoff the turbo.

12Remove the exhaust manifold mount-ing bolts and lift the manifold awayfrom the engine.

13Remove all of the temperature sen-sors.

14

T2007717

Clean the cylinder head and exhaustmanifold contact surfaces.Blow clean with compressed air.

44


15

T2007718

Glue the new gaskets onto the ex-haust manifold with the correct sidefacing the manifold.Note: The marking ”MANIFOLD SIDE”should be turned toward the exhaustmanifold.

16

T2007724

Install 2 alignment dowels in the cylin-der head to help position the manifold.Install the exhaust manifold and thecorresponding bolts.

Note: Make sure that the sleeves areproperly positioned in the counterboreof the manifold flange.

17

W2002224

Tighten all the exhaust manifold boltsto a torque of 48 ± 8 Nm(35 ± 6 ft-lb).

Use the torque tightening sequenceshown.

48 ± 8 Nm(35 ± 6 ft-lb)

18Note: Make sure that all gasket sur-faces on the turbocharger are free ofgasket material and clean. Make surethat there is nothing inside the exhaustmanifold or air piping e.g. debris froma previous failure.Install the turbocharger with a newmounting gasket onto the exhaustmanifold. Torque mounting nuts to48 ± 8 Nm (35 ± 6 ft-lb).

48 ± 8 Nm(35 ± 6 ft-lb)

19Position the shutter housing andexhaust piping onto the rear of the tur-bocharger. Install clamp and torque to24 ± 2 Nm (18 ± 2 ft-lb).

24 ± 2 Nm(18 ± 2 ft-lb)

20Connect the oil return tube (using anew gasket) to the turbocharger.Torque bolts to 24 ± 4 Nm(18 ± 3 ft-lb).

24 ± 4 Nm(18 ± 3 ft-lb)

21Install the oil supply tube with a newseal and gasket. Torque bolts to24 ± 4 Nm (18 ± 3 ft-lb).

Note: Make sure the port in the oil fil-ter housing for the oil supply tube andseal assembly is clean and smooth,also before installing the supply tube,pre-lubricate the turbo with clean en-gine oil.

24 ± 4 Nm(18 ± 3 ft-lb)

45


22Connect the lower charge air coolerpipe and adapter with new O-ringseals to the turbo. Install and torquethe 3 charge air cooler pipe supportbolts to 24 ± 4 Nm (18 ± 3 ft-lb).

Note: To make installation easier, ap-ply a soapy solution to the O-ringsprior to installation.

24 ± 4 Nm(18 ± 3 ft-lb)

23Connect the air compressor oil supplyline and support clamp. Torque theclamp bolt to 24 ± 4 Nm (18 ± 3 ft-lb).

24 ± 4 Nm(18 ± 3 ft-lb)

24Install the heat shield and all of the aircompressor discharge line supportbrackets. Connect the discharge lineto the air compressor. Torque the heatshield bolts to 48 ± 8 Nm (35 ± 6 ft-lb).

48 ± 8 Nm(35 ± 6 ft-lb)

25Install the air filter housing and all airpiping.

26

W2002216

Attach the connector to the exhaustpressure governor solenoid valve.

27Remove the 36-pin breakout harnessand reconnect the EB harness con-nector to the EECU.

2145-06-02-02Rocker Arm Roller, Checking


Special tools: 9996956Other special equipment: 9989876, 9999696

1

T2006672

Install the cranking tool and rotate theflywheel around until the camshaft isin a position where the rocker armroller is not resting on any of thecamshaft lobes.

9996956

2Check that there is a gap between therocker arm roller and the camshaft.

3

T2007948

Rotate the roller a number of turns todisperse the oil film between the bush-ing and shaft.

Note: If the roller seizes, the rockerarm must be replaced.

46


4

T2007949

Install a dial indicator on a magneticbase and position the magnetic baseas level as possible on the rocker arm.Adjust the dial indicator probe horizon-tally against the center of the roller.Set the dial indicator to zero.

Note: Check that the dial indicatormeasuring probe is pre-loaded andpermits movement in both directions.

99998769999696

5

T2007950

Place a screwdriver between therocker arm and roller.Press out the roller as far as possibleand read the value on the dial indica-tor.

6

T2007951

Using a blunt object, press the rollerinwards as far as possible and readthe measurement value on the dial in-dicator.

The max. permitted play between thebushing and the shaft is 0.1 mm(0.004 in). If the play is greater, therocker arm should be replaced.

Max. 0.1 mm(0.004 in)

7

T2007792

If it is necessary to replace a rockerarm, lubricate the new rocker armbushing with engine oil. Use a manualpump oil can and insert the nozzle inthe oil channel hole.

Rotate the roller while pumping oil intothe channel hole. Continue until oilruns out both sides of the roller.

47

Group 25 Service Procedures

Service Procedures2145-04-04-02Rocker Arm, OverhaulSpecial tools: 9996716, 9998344

Repair kit: 8148353

1

T2007725

Remove the plunger from the rockerarm.

Note: The plunger and rocker arm area matched pair and are punch-markedfor identification. They are not to bemixed when reassembled.

2

T2007726

Carefully heat the rocker arm plugs.Remove the plugs and take thesprings, plunger, ball and spring guideout of the rocker arm.

3

T2007727

Press out the ball seat with drift9998344.

Note: Press the ball seating out in thedirection as shown.

9998344

4Clean and check the rocker arm.Make sure that all dirt is removed be-fore assembling.

Note: If the rocker arm shaft bushingor roller is damaged, the completerocker arm must be replaced.

49


5

T2007728

Use drift 9996716 as a counter-hold inthe hole for the non-return valveplunger. Lubricate the new ball seatwith gear oil and press in the seatwith drift 9998344 until it bottomsagainst the counter-hold.Check themeasurement for the ball seat positionin the rocker arm.

Note: Make sure that the ball seat ispositioned with the ring groovetowards the ball and that no metal par-ticles remain after pressing in the seat.

9996716,99983440± 0.1 mm(0± 0.003 in.)

6

T2007729

Lubricate the components with engineoil and install the ball, spring guideand spring. Apply one drop of lockingfluid to the threads of the new plugand install the plug.

Note: Make sure that the plug androcker arm threads are clean and drybefore the locking fluid is applied.Carefully wipe off any excess lockingfluid after the plug is installed.

7

T2007730

Lubricate the non-return valve plungerwith engine oil, check that the plungermoves easily in the rocker arm and in-stall the spring. Apply one drop oflocking fluid to the threads of the newplug and install the plug.

Note: Make sure that the plug androcker arm threads are clean and drybefore the locking fluid is applied.Carefully wipe off any excess lockingfluid after the plug is installed.

8

T2007725

Make sure the rocker arm and rockerarm plunger punch marks are thesame. Lubricate the rocker armplunger with engine oil and install it inthe rocker arm.

Note: Place a rubber band around therocker arm and plunger to prevent theplunger from falling out.

50


9

T2007792

Lubricate the journaling for the rockerarm roller with engine oil. Use a man-ual pump oil can and insert the nozzlein the oil channel hole. Rotate theroller while pumping oil into the chan-nel. Continue until oil runs out bothsides of the roller.

2533-03-02-05Solenoid Valve, CompressionBrake, Replacement


WARNING


WARNING



2

T2006731


51


CAUTION

With older engines, avoid damage to the valve coverand injector cable harness by making sure the mount-ing screws do not unscrew from the cylinder headduring removal. Do not use impact tools to removethe nuts securing the valve cover.

3Clean the area round the solenoidvalve.

4

T2007731

Remove the electrical connectionsfrom the solenoid valve.

5

T2007732

Remove the mounting bolt and flange.Lift off the old solenoid valve.

Note: Check that the drain channel inthe VEB control valve is not clogged.

6

T2007736

Install the new solenoid valve, flange,and mounting bolt.

Note: The solenoid mounting angle isimportant. The terminals of the sole-noid should be at a 0 to 45� angle tothe VEB control valve oil pipe.Torque the solenoid mounting screw to12.2 Nm (9 ft-lb).

12.2 Nm(9 ft-lb)

52


7

T2007733

Connect the electrical cables to thesolenoid valve and tighten the nuts toa torque of 1.4 Nm (1 ft-lb).

1.4 Nm(1 ft-lb)


9

T2007003

Tighten the valve cover nuts to 30 ± 3Nm (22 ± 2 ft-lb). Follow the tighteningsequence shown.

30 ± 3 Nm(22 ± 2 ft-lb)


2531-03-02-02Control Valve, Engine Brake,Replacement


WARNING


WARNING



2

T2006731


Note: With older engines, avoiddamage to the valve cover and injectorcable harness by making sure themounting screws do not unscrew fromthe cylinder head during removal. Donot use impact tools to remove thenuts securing the valve cover.

3Clean the area around the solenoidvalve.

53


4

T2007731

Remove the electrical connectionsfrom the solenoid valve.

5

T2007722

Remove the valve cover stud locatedbeside the VEB control valve.

Note: Use Kent Moore tool J–41203 totorque the studs on early D12 engines.

J–41203

6

T2007734

Loosen the attaching bolts and re-move the control valve.Also remove the oil pipe and seals be-tween the control valve and rockerarm shaft.

7

T2007794

Transfer the solenoid valve to the newcontrol valve, if it is to be re-used.Torque the solenoid mounting screw to12.2 Nm (9 ft-lb).

Note: Check that the drain holes in theVEB solenoid valve are not clogged.The solenoid mounting angle is impor-tant. The terminals of the solenoidshould be at a 0 to 45� angle to theVEB control valve oil pipe.

12.2 Nm(9 ft-lb)

54


8

T2007734

Install new seals on the pipe betweenthe control valve and rocker arm shaft.Press the pipe (together with the seal)into the control valve. Install a newseal in the control valve oil inlet holewhere it mates with the cylinder head.

Install and bolt down the control valve.Make sure that the seals against thecylinder head and rocker arm shaft arepositioned correctly.

Torque the control valve mountingbolts to 20 ± 3 Nm (15 ± 2 ft-lb).

20 ± 3 Nm(15 ± 2 ft-lb)

9

T2007723

Clean the threaded hole in the cylinderhead located beside the VEB controlvalve. Clean the valve cover stud boltand apply locking fluid. Torque thestud to 48 ± 8 Nm (35 ± 6 ft-lb).

Note: Use Kent Moore tool J–41203 totorque the studs on early D12 engines.Carefully remove any excess lockingfluid after the stud bolt has been tight-ened.

J–4120348 ± 8 Nm(35 ± 6 ft-lb)

10

T2007733

Connect the electrical cables to thesolenoid valve and tighten the nuts toa torque of 1.4 Nm (1 ft-lb).

1.4 Nm(1 ft-lb)

11Press the electrical cable clamp ontothe stud bolt.

Note: The electrical cable must be po-sitioned on the outside of the valvecover stud.


13

T2007003

Tighten the valve cover nuts to 30 ± 3Nm (22 ± 2 ft-lb). Follow the tighteningsequence shown.

30 ± 3 Nm(22 ± 2 ft-lb)


55

Operation Numbers

2145-04-04-02 Rocker Arm, Overhaul . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 492145-06-02-02 Rocker Arm Roller, Checking . . . . . . . . . . . . . . . . . . . . . . . . . . 462515-06-02-01 Exhaust Temperature, Checking . . . . . . . . . . . . . . . . . . . . . . . . . 402531-03-02-02 Control Valve, Engine Brake, Replacement . . . . . . . . . . . . . . . . . . . . 532531-06-02-01 Engine Brake, Checking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 272531-06-02-02 Exhaust Brake, Electronic Checking . . . . . . . . . . . . . . . . . . . . . . . 302531-06-02-03 Exhaust Brake, Mechanical Checking . . . . . . . . . . . . . . . . . . . . . . 322533-03-02-05 Solenoid Valve, Compression Brake, Replacement . . . . . . . . . . . . . . . . 512533-06-02-01 Solenoid Valve, Compression Brake, Checking . . . . . . . . . . . . . . . . . . 292533-06-02-02 Oil Pressure, Compression Brake, Checking . . . . . . . . . . . . . . . . . . . 36

Volvo Trucks North America, Inc.P.O. Box 26115, Greensboro, NC 27402-6115

Volvo Trucks Canada, Ltd.6490 Vipond Drive, Mississauga, Ontario L5T 1W8

http://www.volvotrucks.volvo.com

PV776-TSP0250610/2 () 2.2000 © Volvo Trucks North America, Inc., 2000

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