Care must be taken to ensure that fluids are contained
during performance of inspection, maintenance, testing,
adjusting and repair of the product. Be prepared to collect
the fluid with suitable containers before opening any
compartment or disassembling any component containing
Refer to Special Publication, NENG2500, "Caterpillar Tools
and Shop Products Guide" for tools and supplies suitable
to collect and contain fluids on Caterpillar products.
Dispose of all fluids according to local regulations and
Before you conduct the testing and adjusting, refer to the
Stop the machine. Apply the parking brake.
Place the propel control lever in NEUTRAL position.
Drum Drive Motor
(1) Brake line.
(2) Case drain line.
Remove brake line (1) from the drum drive motor. Plug
the brake line and cap the fittings.
Install the 4C-6500 Digital Thermometer into the
hydraulic oil tank. The hydraulic oil temperature must
be 38C (100F) for proper test results.
Disconnect case drain line (2) from the axle motor.
Install 9X-2350 Hose and 4C-8689 Flow Meter to the
axle motor. This allows the leakage oil to flow from the
axle motor through the flow meter and into case drain
Install two 51710 kPa (7500 psi) pressure gauges on
the pressure test ports for the axle propel pump.
To prevent overheating of the hydraulic oil and damage to
the propulsion system components, do not run each test
longer than 30 seconds.
Start the engine. Run the engine at high idle.
Set the speed range switch to the HIGH SPEED
With the propel control lever in NEUTRAL position, read
the amount of oil that is flowing through the flow meter.
The oil flow should be less than 1 gpm.
Release the parking brake.
Slowly move the propel control lever in the FORWARD
position. When the pressure reaches 10342 kPa (1500
psi), the maximum allowable oil flow is 3.8 gpm.
Repeat Step 9 four times. Rotate the wheels for 90
after each reading.
Repeat Steps 7 through 9 while the propel control lever
is in REVERSE position.
If the leakage is more than 3.8 gpm, the axle motor
and/or the flushing valve should be repaired or replaced.
Remove the caps and the plugs. Reconnect brake line
(1) to the drum drive motor.