333390AEN

Kit

MP400/300 Mustang 4800 Pressure Control Replacement Kit

For replacing pressure control assembly for the MP400/300 and Mustang 4800 Airless Paint Sprayers. For professional use only.

Kit 868025120V, MP400 and Mustang 4800

Kit 868026230V, MP400

Kit 868027230V, MP300

3000 psi (20.7 MPa, 207 bar) Maximum Working Pressure

Important Safety InstructionsRead all warnings and instructions in this manual and in your Series A SL unit manual. Save all instructions.

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Instructions

2 333390A

Instructions

Pressure Relief ProcedureFollow the Pressure Relief Procedure whenever you see this symbol.

1. Engage the gun trigger lock. Refer to the separate instruction manual provided with gun for safety fea-tures and how to engage the trigger lock.

2. Turn the unit off.

3. Disengage the gun trigger lock and trigger the gun to relieve residual fluid pressure.

Hold metal part of the gun in contact with grounded metal pail. Use minimum pressure.

4. Re-engage gun trigger lock and turn Prime Valve to the open (priming) position.

NOTE: The valve handle can move both clockwise and counter clockwise and can face different directions.

5. If you suspect the spray tip or hose is clogged or that pressure has not been fully relieved after follow-ing the steps above, VERY SLOWLY loosen tip guard retaining nut or hose end coupling to relieve pressure gradually, then loosen completely. Clear hose or tip obstruction.

Pressure Control Assembly Replacement

Removal

1. Relieve pressure, page 2. Disconnect power cord from outlet.

2. Unlatch and remove pressure control wire cover (22).

WARNINGThis equipment stays pressurized until pressure is manually relieved. To help prevent serious injury from pressurized fluid, such as skin injection, splashing fluid and moving parts, follow the Pressure Relief Procedure when you stop spraying and before cleaning, checking, or servicing the equipment.

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Closed(Pressure)

Open(Priming)

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22

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Pressure Control Assembly Replacement

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3. Remove rubber seal (27) from terminal box (26).

4. Disconnect pressure switch connector from control board.

5. Turn the pressure control (20) counter clockwise to access the flats on either side.

6. Using a wrench loosen and unscrew pressure con-trol assembly.

NOTE: If you plan to reuse the pressure control assem-bly, be careful not to damage or tangle the wire while unscrewing the assembly.

7. Remove pressure control assembly.

InstallationNOTE: Inspect pressure control assembly before instal-lation to verify the o-ring is installed and in place.

1. Apply thread adhesive to the pressure control (20) threads.

2. Thread the pressure control assembly (20) into sprayer. Torque to 150 in-lbs (17.0 N•m).

3. Connect pressure control assembly connector (A) to control board opening of terminal box.

27

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26

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20

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A

Pressure Control Assembly Replacement

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4. Insert rubber seal (27) into opening of terminal box (26).

5. Re-attach pressure control wire cover (22) making sure the whole wire is in the cover.

NOTE: Be careful when tightening pressure control knob that wires do not get pinched between the pres-sure control assembly and pump.

6. Turn the pressure control (20) clockwise to the max-imum pressure position.

7. Apply label (4) to pressure control (20).

NOTE: When properly positioned, the function indicator (fi) and hi-spray position symbol on pressure control label (cl) are aligned.

2726

22

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fi

cl

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4

20

Parts

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Parts

1

3

4

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Ref.Part Number Description Qty

1 CONTROL, pressure, diaphragm 13 LABEL, control 14 LABEL, control, magnum 1

TO Place An Order Or For Service, contact your Airlessco distributor,or call 1-800-223-8212 to identify the nearest distributor.

All written and visual data contained in this document reflects the latest product information available at the time of publication.Airlessco reserves the right to make changes at any time without notice.

For patent information, see www.graco.com/patents.

Original Instructions. This manual contains English. MM 333390

AIRLESSCO • 3501 N. 4TH AVENUE • SIOUX FALLS, SD 57104 • USA

Copyright 2014, Airlessco. All Airlessco Manufacturing locations are registered to ISO 9001.Revision A - March 2014