210. Hydraulic Pump
a. Removal. Refer to paragraph 150b.
b. Disassembly.
(1) Remove the four screws (1) attaching the pump cover (2) to the pump body (9).
(2) Remove the pump cover (2) and plate spring (3).
(3) Remove the pressure plate (4) and seal ring (5). Discard the seal ring.
(4) Lift out and remove the ring (6) and seal ring (5). Discard the seal ring.
(5) Remove the vanes (20) from the rotor (7) and pull the rotor off the shaft (15).
(6) Remove the two bracket bolts (8) and separate the bracket (11) from the pump body (9).
(7) Remove and discard the gasket (10).
(8) Remove the key (16). Spread and remove the retaining ring (17) from the bracket (11).
(9) Pull out the shaft (15) from the bracket (11).
(10) Pull the outer bearing (18) off the shaft.
(11) The oil seal (14) is pressed into the body and must be split into two pieces for removal. Use a cold chisel to
split the oil seal, being careful not to damage the body (9). Remove and discard the oil seal.
(12) Use a small drift punch to drive out the inner bearing (12) and spacer (13) from the pump body (9).
(13) Tap the bearing out from the ring (6) side.
c. Cleaning. Wash all parts in cleaning solvent and dry them with clean compressed air. Make sure that all sludge,
grease, and oil is removed from the parts. Cover the cleaned parts with a clean rag to protect them from dust and dirt.
Clean all mounting screws with a stiff wire brush. Make sure that all machined surfaces are perfectly clean and free of
foreign matter. Even the slightest trace of dirt or foreign matter in the pump will impair its performance. Handle the
cleaned pump parts with clean hands and tools.
d. Inspection and Repair.
(1) Replace all gaskets and oil seal rings.
(2) Inspect the rotor and vanes for wear, cracking, and chipping.
Replace the rotor and vanes if even the slightest trace of wear is found.
(3) Inspect the shaft for twisting, cracks, breaks, a chipped keyway, and damaged, stripped, or broken splines
and threads. Replace the shaft if it is bent or corroded, or if the bearing journals are scored or etched.
319
