RD 12/RD 12A Drive Systemwc_tx000667gb.fm 515.3 Checking the Drive System Operating PressureBackground Failure of the drive circuit to reach operating pressures is normally caused by a worn ordamaged drive pump; however, the problem could also be the result of a badly worn motor.Prerequisites Machine on a firm, level surface 3000-psi pressure gauge Hydraulic oil warmProcedure Follow the procedure below to test the drive system operating pressure.1. Install a 3000-psi gauge in the forward test port (a) on the drive pump.2. Start the engine and run the machine at full throttle.3. Shift the control lever to forward and record the pressure on the gauge.4. Stop the engine.5. Install the gauge in the reverse test port (b) and repeat the procedure while operating inreverse.Note: Operating pressures will increase significantly when running the machine uphill, offroad, or against an object.The drive system operating pressure has now been checked.