28. Main Pump (Flow) - Test - Constant Horsepower Flow Control

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Main Pump (Flow) - Test - Constant Horsepower Flow Control

SMCS - 5070-081-FW

This test measures individual pump flow at the pump. Each pump is tested individually for output flowat specified pressures. The pump that is not being tested is not under load and the pump remains at lowpressure standby.

Cerrar SIS

Pantalla anterior

Illustration 1 g00764798

The electronic control module is located in the compartment behind the cab.

(1) Alarm lamp

(2) Electronic control module


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Note: Before starting main pump flow tests, check message display (4) on monitor (3) and alarm lamp(1) on electronic control module (2) for normal operation. If no faults are present, perform theoperational checks. Refer to Testing And Adjusting, "Operational Checks".

Note: If the operational checks (cycle time) indicate that slow speed of an implement is common to the

circuits of one pump, the problem is most likely in the hydraulic system. Then perform the pump flowtests. Refer to Testing And Adjusting, "Main Pump (Flow) - Test".

Note: The engine, the fuel, or the working altitude may be the problem if the operational checks indicatethat slow speed of an implement is common to both pump circuits.


(3) Monitor

(4) Message display

Table 1

Required Parts

Item Number Part Number Part Description Quantity

5 4C-6482 Nipple assembly 2

6 7M-8485 O-Ring seal 2

7 4I-6141 Coupling 1

9 6V-9746 O-Ring Seal 6

10 6V-9512 Face Seal Plug 1


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12 4I-6140 Coupling 1

14 6V-9853 Swivel Elbow 1

15 6V-9810 Union 1

40 5K-9090 O-Ring Seal 2

41 6V-9832 Cap 1

42 6V-8397 O-Ring Seal 1

43 6V-9508 Face Seal Plug 1


Flow meter tool layout

(8) Delivery line (right pump)

(11) Delivery line (left pump)


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Right Pump

Note: Perform the test for the right pump and the test for the left pump one at a time.

(13) Makeup Line (swing motor)

(16) Swing motor

(17) Right pump

(18) Left pump

(22) Elbow

(23) Valve

(24) Setup of basic flow meter and hoses

NOTICE

Care must be taken to ensure that fluids are contained duringperformance of inspection, maintenance, testing, adjusting and repairof the product. Be prepared to collect the fluid with suitable containersbefore opening any compartment or disassembling any componentcontaining fluids.

Refer to Special Publication, NENG2500, "Caterpillar Dealer ServiceTool Catalog" for tools and supplies suitable to collect and containfluids on Caterpillar products.

Dispose of all fluids according to local regulations and mandates.


Pump Compartment


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1. Position the machine on level ground.

2. Stop the engine.

3. Release the pressure in the hydraulic system. Refer to Testing And Adjusting, "Hydraulic SystemPressure - Release".

4. Install the following tools in accordance with the flow meter tool layout. Refer to Illustration 3.

a. Assemble the basic flow meter and hoses.

Note: Refer to Testing and Adjusting, "Flow Meter and Hose Setup (Basic)" for theprocedure to assemble these parts.

b. Disconnect delivery line (8) from right pump (17) .

c. Install seal (40) and plug (10) to the end of delivery line (8) .

d. Assemble and install nipple (5) , seal (6) , coupler (7) , and seal (40) on right pump (17) .



(17) Right pump

(18) Left pump

(19) Pressure tap (right pump delivery pressure)

(20) Pressure tap (left pump delivery pressure)

(21) Pressure tap (power shift pressure)

(25) Negative flow control line (right pump)


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e. Disconnect makeup line (13) from elbow (22) at swing motor (16) .

f. Assemble and install nipple (5) , seal (6) , coupling (12) , seal (9) , elbow (14) , seal (9) ,union (15) , and seal (9) to makeup line (13) .

g. Install seal (9) and cap (41) to elbow (22) .

h. Connect the portable hydraulic tester between nipple (5) at right pump (17) and nipple (5) atthe swing motor.

i. Connect a 60000 kPa (8700 psi) pressure gauge to pressure tap (19) for right pump deliverypressure.

j. Install a multitach group on the engine. This is used to monitor engine speed.

Left Pump

Note: Perform the test for the right pump and the test for the left pump one at a time.



(16) Swing motor

(22) Elbow

NOTICE

Care must be taken to ensure that fluids are contained during

performance of inspection, maintenance, testing, adjusting and repairof the product. Be prepared to collect the fluid with suitable containersbefore opening any compartment or disassembling any componentcontaining fluids.

Refer to Special Publication, NENG2500, "Caterpillar Dealer ServiceTool Catalog" for tools and supplies suitable to collect and containfluids on Caterpillar products.

Dispose of all fluids according to local regulations and mandates.


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1. Position the machine on level ground.

2. Stop the engine.

3. Release the pressure in the hydraulic system. Refer to Testing And Adjusting, "Hydraulic SystemPressure - Release".

4. Install the following tools in accordance with the flow meter tool layout. Refer to Illustration 3.

a. Assemble the basic flow meter and hoses.

Note: Refer to Testing and Adjusting, "Flow Meter and Hose Setup (Basic)" for theprocedure to assemble these parts.

b. Disconnect delivery line (11) from left pump (18) .

c. Install seal (40) and plug (10) to the end of delivery line (11) .


Pump Compartment



(17) Right pump

(18) Left pump

(19) Pressure tap (right pump delivery pressure)

(20) Pressure tap (left pump delivery pressure)

(21) Pressure tap (power shift pressure)

(38) Negative flow control line (left pump)


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d. Assemble and install nipple (5) , seal (6) , coupler (7) , and seal (40) on left pump (18) .

e. Disconnect makeup line (13) from elbow (22) at swing motor (16) .

f. Assemble and install nipple (5) , seal (6) , coupling (12) , seal (9) , elbow (14) , seal (9) ,union (15) , and seal (9) to makeup line (13) .

g. Install seal (9) and cap (41) to elbow (22) .

h. Connect the portable hydraulic tester between nipple (5) at left pump (18) and nipple (5) atthe swing motor.

i. Connect a 60000 kPa (8700 psi) pressure gauge to pressure tap (20) for left pump deliverypressure.

j. Install a multitach group on the engine. This is used to monitor engine speed.

Test



(16) Swing motor

(22) Elbow

To prevent personal injury or equipment damage from failure of thehydraulic test equipment or associated circuit components because of blocked pump flow, make sure that the test equipment valves are fullyopen before starting the engine.


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1. Start the engine.

2. Place the machine controls at the following settings: engine speed dial "10" and AEC switch OFF.Refer to Testing And Adjusting, "Engine Performance - Test" for engine rpm settings.

3. Increase the hydraulic oil temperature to 55° ± 5°C (131° ± 9°F).

To prevent personal injury and/or equipment damage from failed linesor components while the hydraulic test equipment is returned to theopen flow position, slowly open the hydraulic test equipment valve whilemonitoring the pump flow.

If pump flow does not increase as the valve is opened, shut the engineoff and determine what is preventing the pump from upstroking.


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Monitor

(A) Message display

(B) Keypad

(C) Up key

(D) Left key

(E) Down key

(F) Right key


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4. Start Service Mode and input a fixed power shift pressure of 2400 ± 50 kPa (350 ± 7.5 psi).

a. Press menu key (J) .

Note: If more than thirty seconds pass between pushing the keys on the keypad, the menumode will be cancelled and the previous display will be restored to message display (A) .

b. Press down key (E) in order to highlight the menu item "SERVICE OPTIONS" on themessage display. Press OK key (I) .

c. Input the password "FFF2". Press left key (D) or right key (F) in order to change theposition of the flashing character. Press up key (C) or press down key (E) in order to changethe value of the flashing character. Press OK key (I) after the correct password is displayed.

d. Press down key (E) once in order to highlight the second line on the message display.

e. Press right key (F) repeatedly until "DEVICE TEST" appears on the message display.

f. Press down key (E) in order to move down one line on the message display.

g. Press right key (F) until the "PS PRV - FIXED" appears on the message display.

h. Press down key (E) .

i. Press OK key (I) . The display on line 4 of the message display will now change to anumeric value. These characters represent the power shift pressure (kPa).

j. Press left key (D) or right key (F) in order to increase or decrease the numeric value that isdisplayed on line 4 of the message display. Pressing left key (D) one time decreases thepower shift pressure 10 kPa (1.5 psi). Pressing right key (F) one time increases the powershift pressure 10 kPa (1.5 psi).

Note: The value for power shift pressure on the monitor may not always match the pressure

reading on the pressure gauge. Adjust the value on the monitor until the desired power shiftpressure is attained on the pressure gauge that is connected to the pressure tap for powershift pressure. The actual power shift pressure must be 2400 ± 50 kPa (350 ± 7.5 psi) on thepressure gauge.

Note: To prevent a change in power shift pressure during the pump flow test, do not turnthe engine start switch to the OFF position.

Note: Refer to Service Manual, "Engine And Pump Electronic Control System" for

(G) Cancel key

(H) Set key

(I) OK key

(J) Menu key


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additional information on Service Mode.

5. In order to perform flow measurements for either one of the pumps, the other pump must not beunder load.

6. Turn valve (23) on the portable hydraulic tester clockwise. Record pump flow at each of thefollowing pressures in Table 3. Use pressure tap (19) to monitor right pump delivery pressure or

use pressure tap (20) to monitor left pump delivery pressure.


P-Q characteristic curve

Table 2

Pump Flow Test

Measuring Points

3900 kPa 15700 kPa 17700 kPa 21600 kPa 29400 kPa


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28. Main Pump (Flow) - Test - Constant Horsepower Flow Control

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