PUMP GP-PISTON 3678077 - Caterpillar

1. Drain the oil from the front section of the hydraulic tank.2. Disconnect inlet pipe (4) and outlet hose (2) from the hoist hydraulic pump.3. The weight of hoist hydraulic pump (1) is 25 kg (55 lb.). Fasten a hoist to the hoist hydraulic pump, or use two persons to remove it.4. Remove two bolts (3) and the hoist hydraulic pump.5. Remove the O-ring seal from the hoist hydraulic pump.6. Put the O-ring seal in position on hoist hydraulic pump (1).7. Put hoist hydraulic pump (1) in position, and install two bolts (3) to hold it.8. Connect inlet pipe (4) and outlet hose (2) to the hoist hydraulic pump as shown.9. Fill the hydraulic tank with oil to the correct level. See the Maintenance Guide.Disassemble Hoist Hydraulic Pump
START BY:a. remove hoist hydraulic pump 1. Clean the outside of the pump thoroughly. Put a mark on the pump body and flange so they will not be mixed at assembly.2. Remove O-ring seal (1).3. Remove eight bolts (3) and the washers. Remove flange (2) from the pump body. 4. Remove O-ring seal (4) from the bottom of the flange. 5. Remove two lip seals (5) and the ring from the top of the flange. 6. Remove isolation plate (7), ring retainer (6), O-ring seal (8) and back-up ring (9) from the pump body. 7. Lift the drive gear until upper pressure plate (10) is removed from the pump. Put the drive gear back in position in the pump, and remove pressure plate (10). 8. Remove drive gear (11) and idler gear (12) from the pump body.
Use care when lower pressure plate (13) is removed. Keep the pressure plate as level as possible when it is removed. Do not use force to remove the plate or damage to the pressure plate or pump bores can be the result.
9. Remove lower pressure plate (13). 10. Remove isolation plate (15), ring retainer (14), O-ring seal (16) and back-up ring (17) from the pump body.Assemble Hoist Hydraulic Pump
1. Make sure all the pump parts are clean and free of all dirt or foreign material.2. Put clean SAE 10 oil in the bores of the pump body.3. Install lower isolation plate (2) in the pump body on the inlet side of the pump. Make sure the round edge of the isolation plate is toward the bottom of the pump.4. Install back-up ring (4), O-ring seal (3) and ring retainer (1) in the pump body.
Keep pressure plate (5) as level as possible when it is installed in the pump body. Do not use force on the plate to put it into position or damage to the plate or pump bores can be the result.
5. Install lower pressure plate (5) in the pump body with the machined groove (slot) toward the outlet side of the pump. Make sure the bronze side of the pressure plate is toward the gears. 6. Put idler gear (7) and drive gear (6) in position in the pump body. 7. Install upper