Match-mark the cover, ring, and body to
Inspect the face of the pressure plate that
assure proper Reassembly.
rides on the vanes for scoring. Lap out scores with
Clamp the drive gear lightly in a soft-jawed
crocus cloth. Replace the pressure plate if scores
cannot be removed.
vise to prevent the shaft from rotating while removing the
Inspect the bearings for wear, pitting, and
After removing the cover (2), ring (7), and rotor
looseness; replace damaged bearings.
Inspect the shaft for distortion, worn or
(8), remove the retaining ring (11) and press on the
damaged splines, and damaged threads. Check the
splined end of the shaft (14) to remove the assembled
keyway for burrs. Remove any burrs with a fine stone.
shaft and bearing (15) from the body (18).
Pry the seal (17) from the body (18) with a thin,
Inspect all other parts for cracks, distortion,
worn or damaged threads, and other damage; replace
Dry cleaning solvent, P-D-680, used to clean
parts is potentially dangerous to personnel and
Refer to figure 4-2 and reassemble the main hydraulic
property. Avoid repeated and prolonged skin
pump. Note the following:
contact. Do not use near open flame or
excessive heat. Flash point of solvent is 100°
Lubricate all parts with clean engine oil at
F. - 138° F (39° C. - 59° C.).
Install the seal (17) with the lip facing inward in
Cleaning and Inspection
Align the match-marks made on the cover (2),
Discard the seal and preformed packings.
ring (7), and body (18) during disassembly.
Thoroughly clean all parts of the pump
When installing the splined end of the shaft
assembly, except the bearings, in cleaning solvent P-D-
(14) through the seal (17), apply a thin layer of
680, and shake excess solvent from the parts and dry
cellophane tape over the splines to prevent cutting the
with compressed air.
Clean the bearings by placing them in a wire
Torque the screws (1) evenly and alternately to
basket and agitating them in clean solvent. Dry with
a torque of 65 to 75 ft/lbs.
compressed air taking care not to spin the dry bearings.
Install gear and nut on pump shaft. Stake nut
Dip in engine oil to lubricate the bearings.
Do not use a cloth to wipe the pump parts
Install the assembled pump and adapter and
because lint trapped in the parts can enter the
the gasket on the engine backing plate (para 9-21).
hydraulic system at Reassembly.
Connect the hydraulic lines to the hydraulic
pump (TM 10-3930-632-12).
Inspect the ring, rotor, and vanes for wear,
scoring, distortion, or other damage. Replace the ring,
rotor, and vanes in complete sets only, if damaged.
Refer to figure 4-3 and test the hydraulic pump as
No side play is allowable in vane movement in
the rotor slots.