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| Illustration 1 | g00325363 |
(1) Pump section for the pulled unit (front section) (2) Pump for rear brake cooling (rear section) (3) Inlet from the hydraulic tank | |
The pulled unit hydraulics and rear brake cooling gear pump is a two-section gear pump. The front section (1) is rated at 390 L/min (103 US gpm). Oil from the torque converter, pulled unit, and brake section of the hydraulic tank flows to the pump inlet (3). Pump section (1) then pumps oil to a screen. The oil goes from the screen to the pulled unit control valve. The pulled unit control valve is located in the torque converter, pulled unit, and brake section of the hydraulic tank. The pulled unit control valve will send pump oil to one of two locations. When the hoist control for the pulled unit is in the OPEN or CLOSED position, the pulled unit receives the oil. If the hoist control for the pulled unit is in the FLOAT or HOLD position, the oil flows to the oil cooling system for the rear brakes.
The rear section (2) of the pump is rated at 175 L/min (46 US gpm). Oil from the torque converter, pulled unit, and brake section of the hydraulic tank flows to the pump inlet (3). Pump section (2) then pumps oil to a junction block. The junction block sends the oil to one of two locations. The oil can go through a screen and a filter to the pulled unit brake cooling system. The oil can go to the rear brake cooling system.