VALVE GP-SOLENOID 2839557 - Caterpillar

Illustration 1 g00331808
Location of the pump for the torque converter, parking brake release, and brake cooling (1) Torque converter scavenge section (2) Torque converter charging section (3) Parking brake release section (4) Rear brake cooling section (5) Cover for scavenge screenThe following four sections are included in this pump.
Torque converter scavenge section (1)
Torque converter charging section (2)
Parking brake release section (3)
Rear brake cooling section (4) The pump is driven by a gear on the torque converter.Torque converter scavenge section (1) is located on the drive end. This pump section takes oil from the bottom of the torque converter housing. The oil flows through the scavenge screen behind cover (5). The oil is then returned to the hydraulic tank.The other three pump sections (2), (3), and (4) get oil from the hydraulic tank. The inlet side of the torque converter charging section (2) and the inlet side of the parking brake release section (3) are connected.Torque converter charging section (2) sends the oil to the torque converter hydraulic filter, to the torque converter inlet relief valve, and to the torque converter.Parking brake release section (3) sends oil to the parking brake release hydraulic filter. This oil flow is then divided. Some of the oil flows to the parking and secondary brake valve. This oil is used to release the spring applied parking brakes. The rest of the oil that was divided flows to the lockup clutch and synchronizing valve and the traction control valve. This oil is used to engage the lockup clutch in the torque converter. The oil that is sent to the traction control valve is used as signal oil.Rear brake cooling section (4) sends oil to a junction block. At the junction block, the oil combines with oil from the hoist control valve. This combined oil flows through a screen. Oil from the hoist diverter valve flows through a similar screen. The oil from the junction block and the oil from the hoist diverter valve is now combined. This oil flows through one of two rear brake oil coolers. This oil then flows to the rear wheel brakes. After cooling the rear brakes, the oil returns to the hydraulic tank.