Toro Greensmaster 3120 Service Manual page 95

Traction Circuit Testing – Traction Pump (P1) Flow and Relief
Pressure Test (continued)
Greensmaster 3120
17230SL Rev C
5. Disconnect hose from traction pump "A" port; refer to
6. Install tester in series with the pump and the disconnected hose. Make sure
the tester is installed in the correct flow direction and the tester flow control
valve is fully open.
7. Start engine. Move throttle to full speed (2850 ± 50 RPM).
8. Make sure hydraulic fluid is at normal operating temperature by operating the
machine for approximately 10 minutes.
9. Verify and record engine speed with a phototach.
Use extreme caution when performing this test. The traction unit
wheels will be rotating during the test.
10. Verify pump flow at No Load as follows:
A. Slowly depress forward traction pedal to full forward position.
B. Unrestricted pump output should be approximately 54.9 LPM (14.5
GPM). Record tester pressure and flow readings.
11. Verify pump flow Under Load as follows:
A. Slowly depress forward traction pedal to full forward position.
B. Apply an additional load of 6890 to 10340 kPa (1000 to 1500 PSI) by
slowly closing the flow meter.
C. Record tester pressure and flow readings.
12. Verify traction pump relief valve operation as follows:
A. With the traction pedal in the neutral position, fully close the flow meter
flow control valve.
B. Slowly depress the traction pedal toward the forward position.
C. System pressure should reach approximately 20340 kPa (2950 PSI)
before the relief valve opens. Record tester pressure reading.
Note: The relief valve setting is 19995 kPa (2900 PSI). An additional 345
kPa (50 PSI) is necessary to overcome system charge pressure before
the relief valve opens.
D. Release traction pedal, open flow control valve fully, move throttle to low
speed and turn the engine OFF.
13. If relief pressure can not be met or is greater than specified, the forward
direction traction relief valve is faulty and should be replaced.
14. The Under Load test flow reading (step 10) should not drop more than 12%
when compared to the No Load test flow reading (step 11). A difference
of more than 12% may indicate the traction pump is worn and should be
repaired or replaced.
15. Remove tester and reconnect hydraulic hose to pump "A" port.
16. Check fluid level in hydraulic tank and adjust as necessary; refer to traction
unit Operator's Manual.
CAUTION
Page 4–49 Hydraulic System: Testing the Hydraulic System
Figure 34.