Section IV. REPAIR OF HYDRAULIC PUMP
3-5. Hydraulic Pump.
Throughout the entire operation, hands, parts, tools
and immediate area must be kept clean. introduction
of foreign material into the system may damage or
hinder its operation.
Do not operate the hydraulic motor at maximum by-
pass pressure for extended periods of time since this
will cause overheating of hydraulic oil and result in
Recommended relief pressure 4000 to 4500 psi.
For accessibility, removal of bar box or center plat-
form is recommended.
Equipment Required for Hydraulic Motor Pressure check:
5000 psi pressure gage with a 2 ft. length of high pressure hose to fit gage fitting and
Use suitable adapter to connect 5000 psi gage to motor.
Initial Pressure Check.
On bottom of hydraulic motor remove right hand, nine sixteenth inch plug.
In this opening install a minimum capacity 5000 psi gage using appropriate adapter with
high pressure hose.
(3) Lock hydraulic motor by the following means and take a pressure reading.
On instrument stand in truck cab pull pump control knob to its uppermost position.
Adjust fine control tube up until it is against bottom of hydraulic control knob.
At the rear of distributor lock universal coupling between pump and hydraulic motor
with a pipe wrench of sufficient length to lay against left distributor frame.
Set tachometer to minimum of 1000 RPM.
Engage PTO. (Refer to TM 5-3895-371-10.)
Pull out rear override control until hydraulic motor pressure registers the highest read-
ing. This is by-pass pressure.