Figure 5K-2. Motor Operation
7. Reconnect the drain line upon completion of the test.
whether or not to replace the motor, however, must be
based on what torque and speed you consider to be satis-
To remove the motor, proceed as follows:
To measure the motor tail drain leakage, proceed as
1. Disconnect all the hydraulic lines attached to the motor,
and cap the ends of the hydraulic lines to prevent the entry
1. Disconnect the motor drain hose attached to the end of
of dirt into the hydraulic system. Plug the motor ports to
prevent the entry of dirt into the motor.
2. Install a short piece of hose to the motor drain fitting,
2. Remove the capscrews which secure the motor to the
and insert the opposite end of the hose in a suitable con-
winch. Pull the motor straight out until the motor shaft is
tainer having a capacity of approximately 5 gallons (18 I).
clear of the winch. Remove the motor to a suitable work
3. Unreeve the hook block, if necessary, to reduce the
receiving to a single part of line. Attach the winch line to a
choker chain attached to the towing hooks under the front
bumper. Take up the slack to stall the winch motor.
It is recommended that the motor be replaced with a
4. Start the engine and run it at high idle.
new motor, since the time required to replace the
motor is less than that required to overhaul it. It
5. Pull the winch lever back fully, and hold it for 20
should also be noted that the volumetric efficiency of
an overhauled motor will always be lower than that
of a new motor.
The motor must remain stalled for the full 20
GENERAL. It is suggested that before any work is done on
6. Measure the amount of oil that drained into the con-
this unit, all the steps for disassembly and reassembly be
miner in that 20 second period. Three gallons drained in a
read carefully and understood.
20 second period represents an 80 percent efficiency level;
Expendable parts such as oil seals, back-up rings, O-rings,
more than 3 galIons represents a lower efficiency level; and
sealing strips, and separators should never be re-used even
less than 3 gallons represents a higher efficiency.