WHEEL & TIRE GP 3728391 - Caterpillar

Illustration 1 g00791657
Location of the rear brake oil cooler
The rear brake oil cooler is located on the right side of the engine. Engine coolant from the water pump flows through the rear brake oil cooler. Then, the engine coolant flows back to the cylinder block.The rear brakes are cooled by oil. The cooling oil comes from the hoist and brake gear pump.The oil flow from the hoist section of the hoist and brake gear pump will flow to the hoist control valve. When the hoist control in the cab is in either the HOLD or the FLOAT position, oil will flow through the hoist control valve to the rear brake oil cooler. After the oil goes through the rear brake oil cooler, the oil will flow to the rear brakes. After the oil flows to the rear brakes, the oil will return to the hoist and brake hydraulic tank.The oil flow from the brake section of the hoist and brake gear pump will flow to the parking and secondary brake valve. There is a relief valve in the parking and secondary brake valve. When the pressure of the oil reaches the pressure setting of the relief valve, the pressure oil will flow past the relief valve to the rear brake oil cooler. After the oil goes through the rear brake oil cooler, the oil will flow to the rear brakes. After the oil flows to the rear brakes, the oil will return to the hoist and brake hydraulic tank.The rear brake cooling circuit has a rear brake oil cooler relief valve in the hoist control valve. The rear brake oil cooler relief valve controls the maximum pressure in the rear brake cooling circuit.