(6) Remove pump from vise and turn pump
(5) Repeat steps (2), (3) and (4), above, for
shaft-end up. Shake pump to remove slip-fit gears (23)
installing diaphragm seal, protector gasket, backup
gasket, and diaphragm to body adaptor (26). The steel
(7) Remove key from drive gear shaft.
balls and springs are not used in the body adaptor. The
(8) With rubber mallet, tap splined end of
intake hole in the diaphragm must be aligned over the
drive gear shaft to separate front plate from body.
intake hole in the face of the body adaptor.
Remove drive gear and idler shaft from front plate.
(6) The entire diaphragm must fit inside the
(9) Lift diaphragm (11, backup gasket (10),
raised rim of the diaphragm seal (25)
protector gasket 19) and diaphragm seal (8) from front
(7) Slide gear assemblies (13 and 14) through
plate and adaptor body assembly. Remove steel balls
front plate bearings.
and springs from front plate.
(8) Apply a thin coat of heavy grease to both
(10) With a drift pin, remove dowel pins i16}
milled faces of body. Slip body over gears onto front
securing body and body adaptor.
plate. Half-moon port cavities in body must face away
(11) Separate body and adaptor.
from the front plate. The small drilled hole in one of the
c. Cleaning and Inspection.
cavities must be on the pressure side of the pump.
(1) Clean all parts in an approved solvent and
(9) Slide body adaptor over gear shaft and tap
thoroughly dry with compressed air. Remove any nicks
into place with rubber hammer. Install key on drive shaft
or burrs from parts with emery cloth.
and slide slip fit gears (23) onto shafts.
(2) Inspect drive gear shaft for broken keyway
(10) Coat both milled surfaces of slip fit gear
or damaged splines. The drive gear shaft and idler gear
body (22) with a thin coat of heavy grease. Slide body
shaft must be inspected in bearing and seal areas for
over gears onto body adaptor. Half-moon cavities in
rough surfaces and excessive wear. If shafts measure
body must face away from body adaptor. Small drilled
less than 0.6850 inch in bearing area, the gear assembly
hole in one of the cavities must be on pressure side of
must be replaced. (One gear assembly may be replaced
Shafts and gears are available as
(11) Position back plate (17) onto slip fit gear
body. Secure pump sections together with screws (18,
(3) Inspect the drive, idler, and slip fit gear
19, and 20). Tighten screws to 25 foot-pounds.
Note. The two 4 1/2 inch, 12-point screws are
faces for scoring and excessive wear. If the gear width
installed on each side of the pressure port. The two 4
of the drive gear assembly and idler gear assembly is
1/2 inch, hex head screws are installed directly opposite
less than 0.767 inch, the gear assemblies require
the 12-point screws. The 4 1/4 inch screws are installed
replacement. If the slip fit gear width is less than 0.371
in the remaining positions in the back plate.
inch, the gears must be replaced.
Position port gasket (2) and port adaptor
(4) Measure the inside diameter of the
(1) to pump housing with lock washers (4) and screws
bearings in the front plate or adaptor plate. The front
(3). Tighten screws to 10-12 foot-pounds.
plate or body adaptor require replacement if the inside
Tape drive gear shaft splines and work
diameter of the bearings exceeds 0.691 inch.
shaft seal over shaft into position in back plate. Oil the
(5) The gear pockets in the gear bodies must
seal liberally when installing. Take care not to damage
be checked for excessive scoring or wear. The bodies
oil seal rubber lip.
should be replaced if the inside diameter of the gear
Rotate pump shaft by hand or with
pocket exceeds 1.719 inches.
pliers. Pump will have a small amount of drag, but
should turn freely after short period of use.
(1) Before reassembling pump, clean each
e. Hydraulic Pump Specifications.
part in an approved solvent. Thoroughly dry each part
with compressed air and coat each part with clean
hydraulic oil. All seals, gaskets, and diaphragms should
be replaced with new parts. Be careful to keep parts
clean during reassembly.
GPM at 2015 RPM: 2.3 (1500 psi)
9.5 1500 psi)
(2) Tuck diaphragm seal (8, fig. 3-31) into
0.33 cu in / rev
1.25 cu in / rev
grooves in front plate assembly (5) with open part of "V"
Rotation (viewed from
drive gearshaft end): Clockwise
(3) Press gasket protector (9) and backup
gasket (101 into diaphragm seal. Drop steel balls into
3-25. Hydraulic Pump Motor
seats in front plate assembly and position springs over
a. General. The hydraulic pump motor is a sealed,
ball bearing type motor. The pump motor is compound
(4) Place diaphragm (11) on top of backup
wound for uniform speed, maximum pump life, and
gasket, bronze face up.
smooth hydraulic control. The pump motor is located to
the right of the drive