TM 5-3895-359-14&P
SUBSECTION 7 HYDRAULIC PUMP
bottom section of reservoir, so the reservoir content will
GENERAL
run out this line due to the pump being located lower
The pump supplies oil to actuate the crane cylinder,
than the reservoir, for self-priming purposes.
tailboard cylinder, spray bar ram, pump valve and fifth
wheel cylinder.
a. Remove supply and pressure lines from fittings
OPERATION
on hydraulic pump.
The oil from the reservoir flows by gravity to prime the
b. Remove the nuts and washers from pump
oil pump on the engine. With the engine in operation
casting base on diesel engine. Slide pump out of
and the control valves in neutral, oil flows under pump
mount. The connecting drive sleeve coupling may
displacement from the reservoir, through pump and
slide out with pump gear. This coupling can be slid
through open center passages of valve back to the
back into mesh with drive plate, before
reservoir. When the operator moves the hydraulic
reinstallation.
crane the pump location. The line is attached to the
FIGURE 1
valve handle to raise or lower the crane, oil flows from
c.
Place pump assembly in a vise or fixture,
the reservoir to the pump, into the control valve, to "up"
after cleaning externally with cleaning solvent.
or "down" side of hydraulic ram and exerts pressure on
Grip by mounting flange. Protect flange with
copper or wood guard in vise jaws. Mark cover
ram piston to "raise" or "lower" the crane. The hydraulic
housing and adapter with a prick punch for proper
hose attached to the ram on the opposite side of piston
assembly reference.
from where hydraulic pressure is being applied returns
oil to the valve and back into the reservoir.
d.
Remove the four cover cap screws. Remove
the cover which may come off separately or with
a. The hydraulic pump is mounted on the rear of
the housing.
the diesel engine. The pump is a positive displacement
gear type unit. The pump is capable of running at
e.
To prevent possible leakage, avoid scoring or
speeds of 2500-3000 RPM and pressures to 2000 P.S.I.
nicking machine surfaces of pump sections. Do
not use a screw driver to pry the sections apart.
It will put out the system required pressure at 500 RPM
Tap with a fibre hammer if necessary to loosen.
(1200 P.S.I., 2.2 Gals. per minute).
f.
Note position of relief pocket and drilled holes
PUMP REMOVAL
in the wear plates for proper reassembly. Mark
The pump is mounted onto an adapter plate at the
the drive and driven pump gears with an india
rear accessory drive section of the diesel engine.
stone. See Figure 4 for proper reassembly. Note
Before removing the pump, prepare to catch the
the location and number of gaskets, when
hydraulic oil from the supply line to the pump, at
disassembling.
7-1
