PLATE & FILM GP 1400125 - Caterpillar

Illustration 1 g03419811
Under Operator Platform
(1) Propel pump Propel pump (1) is located under the operator platform. This pump is driven by the engine. A panel on the right side of the machine provides access to this component.Propel pump (1) is a piston-type pump with variable displacement. The pump housing contains a single rotating group that provides flow to the propel motors.
Illustration 2 g03419825
Propel Pump
(2) Proportional solenoid "A"
(3) Proportional solenoid "B"
(4) Port "X2"
(5) Port "X1"
(6) Port "P"
(7) Port "MA"
(8) Port "MB"
(9) Reverse relief valve
(10) Forward relief valve
(11) Interlock solenoid
(12) Port "FE"
(13) Port "B"
(14) Port "A" Each port in the pump housing is identified by a numeric or an alpha-numeric designation which is cast into the housing next to the port. The function of each port is as follows:
Port "A" (14) - This port is a system port. Port "A" is the reverse pressure port for the propel system.
Port "B" (13) - This port is a system port. Port "B" is the forward pressure port for the propel system.
Port "P" (6) - This port directs oil from the interlock valve to the propel motors in order to release the parking brakes.
Port "FE" (12) - This port is the charge inlet port. Filtered charge oil is directed into port "FE".
Port "MA" (7) - This port is a gauge port for reverse pressure.
Port "MB" (8) - This port is a gauge port for forward pressure.
Port "X1" (5) - This port is plugged. Port "X1" (5) can be used to measure reverse servo pressure.
Port "X2" (4) - This port is plugged. Port "X2" (4) can be used to measure forward servo pressure. The direction control valve is equipped with two proportional solenoids. Proportional solenoid "B" (3) controls forward operation of the propel pump. Proportional solenoid "A" (2) controls reverse operation of the propel pump.The propel pump is equipped with two combination valves. Each combination valve contains a makeup valve and a relief valve. The relief valves limit the pressure in the circuit to 38000 2000 kPa (5500 290 psi) nominal pressure. The makeup valves allow charge oil to flow into the low-pressure circuit in order to replenish the oil lost to internal leakage.The interlock valve is located inside the propel pump. The machine ECM number-one controls this solenoid-operated valve. When the parking brake is engaged, solenoid (11) is not energized. When the parking brake is released, the solenoid is energized. When interlock valve solenoid (11) is energized, charge oil is available at the direction control valve of the propel pump. Charge oil is also sent to the parking brakes. When the solenoid is not energized, charge oil is blocked. In this case, the direction control valve and the parking brakes are open to case drain. Under these conditions, the rotating group of the propel pump is at zero angle, and the parking brakes are engaged.
Illustration 3 g03419843
Propel Pump Cross Section
(15) Servo piston
(16) Drive shaft
(17) Swashplate
(18) Slipper pad
(19) Piston
(20) Barrel assembly
(21) Port plate Engine rotation turns pump drive shaft (16), which then rotates barrel assembly