Rear Brake Cooler
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| Illustration 1 | g00988526 |
(1) Rear brake oil coolers | |
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| Illustration 2 | g00988524 |
Rear brake oil coolers (1) are located on the left side of the machine. Engine coolant from the water pump flows through rear brake oil coolers (1). Then, the engine coolant flows back to the cylinder block.
The rear brakes are cooled by oil. The cooling oil comes from the control valve for the hoist and for the brake cooling. Under certain conditions, the cooling oil also comes from the rear brake cooling pump sections in the hydraulic tank.
A screen (2) for rear brake oil cooler (1) is located behind the plug.
The gear pump for the hoist and for brake cooling sends oil to the control valve. When the control valve for the hoist and for brake cooling is in the HOLD position or in the FLOAT position, the oil flows through the control valve to the diverter valve.
When the temperature status is VERY HOT or when the high speed braking status is active, the diverter valve will send the oil through screen (2) for rear brake oil coolers (1). The oil then flows to rear brake oil coolers (1). In other situations, the diverter valve will send the oil through the oil cooler bypass. In either situation, the oil will then flow to the rear brakes. After the oil flows to the rear brakes, the oil will return to the hydraulic tank.
When the rear brake cooling pump sections are driven, cooling oil flows through the screen into rear brake oil coolers (1). Refer to Systems Operation, "Machine Electronic Control Module (Brake/Cooling)" for information about the logic that controls the piston pump that drives the motor and for the solenoid valve for the brake diverter valve.
After the oil goes through rear brake oil coolers (1), the oil flows to the rear brakes. After the oil flows to the rear brakes, the oil will return to the hydraulic tank.
The oil cooler relief valve for the rear brake cooling is located in the hydraulic tank. The oil cooler relief valve is located on the outlet line for the rear brake cooling pump sections. The relief valve prevents excessive pressure from the gear pump sections. The relief valve opens when the oil pressure exceeds the relief pressure.
The oil cooler relief valve for rear brake cooling is located on the control valve. The oil cooler relief valve prevents excessive pressure from the front two sections of the gear pump. The relief valve opens when the oil pressure exceeds the relief pressure.