Toro Groundsmaster 4500-D Series - Page 153

ProcedureforTractionCircuitReliefPressureTest(continued)
g308279
Figure63
1.Forwardreliefvalve5.Straighttting
2.Reversereliefvalve6.90ºtting
3.Piston(traction)pump7.Diagnostictesttting
4.Reversetractionport
3.Locatetractioncircuittestttingforfunctiontobechecked(forwardor
reverse):
A.Fortestingtheforwardtractioncircuit,atestttingislocatedona
hydraulictubeontherightsideofthemachinebelowthehydraulicoil
lter(Figure62).
B.Fortestingthereversetractioncircuit,atestttingneedstobetemporarily
installedinthepiston(traction)pumpreversetractionportonleftsideof
pump(Figure63).Thoroughlycleansideofpumparoundplugtoprevent
systemcontamination.Removeplugfrompumpreversetractionportand
theninstallstraighttting,90ºttinganddiagnostictestttingintopump
port(seeSpecialT ools(page2–16)forttingpartnumbers).
4.Connecta700bar(10,000PSI)pressuregaugetotractioncircuittesttting
forfunctiontobechecked(forwardorreverse).
5.Starttheengineandincreaseenginespeedtohighidlespeed.Makesure
thattractionspeedisintheHI(transport)range.Releaseparkingbrake.
6.Whilesittingonseat,applybrakesfullyandslowlydepressthetractionpedal
intheappropriatedirection(forwardorreverse).Whilepushingtractionpedal,
identifypressurereadingongaugeasreliefvalveopens:
GAUGEREADINGTOBE:
Forward:283to317bar(4100to4600PSI)
Reverse:328to362bar(4750to5250PSI)
7.Releasetractionpedalandstopengine.Recordtestresults.
8.Iftractionpressureistoolow,makessurethatbypassvalveontractionpump
isfullyseatedandtheninspecttractionpumpreliefvalveinpiston(traction)
pump(Figure63).Cleanorreplacevalvesasnecessary.Thesecartridge
typevalvesarefactorysetandarenotadjustable.Ifreliefvalvesareingood
condition,piston(traction)pump,wheelmotorsand/orrearaxlemotorshould
besuspectedofwearandinefciency.
Groundsmaster
®
4500-D/4700-D
Page5–51
HydraulicSystem:Testing
19245SLRevA