GOV & FUEL INJ PUMP GP 7C2569 - Caterpillar

1. Remove the bolts that hold plate assembly (1) to the scraper.2. Disconnect the wiring harness from the ground shut-off switch (2).3. Remove plate assembly (1) from the scraper.
To prevent possible personal injury, make sure all the pressure is released from the air system before any lines are disconnected.
3. Put identification marks on all the hoses for correct installation.4. Disconnect brake signal hose (3), brake actuator hoses (4) and supply hose (5) from relay valve (6).5. Disconnect the wiring harness to the brake relay valve.6. Remove the mounting bolts and relay valve (6) from the scraper.Install Brake Relay Valve (657E Scraper)
1. Put relay valve (1) in position on the scraper and install the bolts that hold it.2. Put 5P-3413 Pipe Sealant with Teflon on the threads of the hoses.3. Connect brake signal hose (2), brake actuator hoses (3) and supply hose (4) to the relay valve. 4. Connect the wiring harness to the ground shut-off switch (5) on plate assembly (6).5. Install the bolts that hold plate assembly (6) on the scraper. Refer to the Operation & Maintenance Manual for all fluid capacities and the proper filling procedures.Disassemble Brake Relay Valves
Start By:a. remove brake relay valve 1. Remove screw (1) and diaphragm (2) from the valve body. 2. Remove four screws (3) and exhaust cover (4) from the body.3. Remove retaining ring (5). 4. Remove washer (11), O-ring seals (8), O-ring seal retainer (10), spring (7), valve retainer (9) and valve (6) from the cover. 5. Remove four bolts (12) from the body. Remove body (13). 6. Remove relay piston (14) from cover assembly (15). 7. Remove fitting (16) from cover (15). 8. Remove diaphragm (17) from the cover.Assemble Brakes Relay Valves
1. Check all O-ring seals for damage. Make a replacement of the O-ring seals if necessary. Thoroughly clean all valve components.2. Install diaphragm (1) and fitting (2) on the cover. 3. Install the O-ring seal on piston (3). Install the relay piston in cover assembly (4). 4. Install body (5) on cover (4). Install the four bolts that hold the unit together. 5. Install valve (6), valve retainer (10), spring (7) and O-ring seal retainer (11). Install O-ring seals (8), washer (12) and retaining ring (9). 6. Install exhaust cover (13) on the cover. 7. Install diaphragm (14) on the exhaust cover.End By:a. install brake relay valve