Repair manual

Troubleshooting the Drive System RD 27
wc_tx000949gb.fm 60
4.7 Checking the Drive System Operating Pressure
Prerequisites  Machine on a firm, level surface
 350-bar (5000-psi) pressure gauge
 Hydraulic oil warm
Background Failure of the drive circuit to reach operating pressures is normally caused by a
worn or damaged drive pump; however, the problem could also be the result of a
badly worn motor.
Procedure Follow the procedure below to test the drive system operating pressure.
1. Install a 350-bar (5000-psi) gauge in the forward test port (a).
2. Start the engine and run the machine at full throttle.
3. Shift the control lever to the FORWARD position and record the pressure on the
gauge.
The pressure should spike at approximately 207 bar (3000 psi) then settle into an
operating pressure range of 55–83 bar (800–1200 psi).
Note: Operating pressures will increase significantly when running the machine
uphill, off road, or against an object.
4. Turn off the engine.
5. Install the 5000-psi gauge in the reverse test port (b) and repeat the procedure
while operating in reverse.
Operating pressures lower than those listed indicate a failing drive motor. Higher
pressures than those listed indicate a problem with the drive motors.
Result The drive system operating pressure has now been checked.