Service Manual

Rev. J
Greensmaster 3250--D
Hydraulic System (Rev. I)
Page 4 -- 35
Procedure for Traction Drive Hydrostat (P3) Flow
Test
This test measures hydrostat pump output (flow). Dur-
ingthistest,pumploadiscreatedattheflowmeterusing
the adjustable load valve on the tester.
1. Make sure hydraulic oil is at normal operating tem-
peraturebyoperatingthemachineforapproximatelyten
(10) minutes.
2. Park machine on a level surface with the cutting
units lowered and off. Make sure engine is off. Make
sure the hydraulic tank is full.
CAUTION
Before continuing further, read and become fa-
miliar with Precautions for Hydraulic Testing.
3. Makesurethattractionpedalisadjustedtotheneu-
tralposition(seeTractionPedalintheAdjustmentsSec-
tion). Also, ensure that pump is at full stroke when
traction pedal is pushed into fully forward position.
4. Block up front wheels off the ground (also rear
wheel if machine is equipped with 3WD) to allow flow
through the traction circuit.
5. Disconnect hose from the upper hydraulic fitting on
the side of the hydrostat.
6. Install tester with pressure gauge and flow meter in
series with the pumpand the disconnected hose. Make
sure flow control valve on the tester is fully open.
7. Make sure functional lever is in the transport posi-
tion.
8. Startengine and move throttle tofullspeed (2750 +
50 RPM) position.
CAUTION
Thedrive wheels willbe off theground androtat-
ing during this test. Make sure machine is well
supported so it will not move and accidentally
fall to prevent injuring anyone near the machine.
9. Slowly push traction pedal into fully forward posi-
tion.
10. Slowlycloseflowcontrolvalveuntilpressuregauge
reads 1000 PSI (69 bar).
11. Observeflowgauge.TESTERREADINGshouldbe
a minimum flow of 12.5 GPM. Record test results.
12. Releasetractionpedal,opencontrolvalveontester,
and turn off machine.
13. If specifications are not met consider the following:
A. The traction pedal and/or traction speed may
need adjustment (see Traction Pedal in the Adjust-
ments Section).
B. The hydrostat needs to be repaired or replaced
as necessary.
C. Makenecessaryrepairsbeforeperformingaddi-
tional tests.
14. If specifications are met, check wheel motor effi-
ciency( see WheelMotorEfficiency Testin thissection).
15. If testing is complete, disconnect tester from pump
fitting and hose. Reconnect hose to pump fitting.
Hydraulic
System