Service Manual

Troubleshooting
Thefollowingchartcontainsinformationtotroubleshoothydrauliccircuit
problems.Therecanbemorethan1causeforamachinemalfunction.
RefertoT estingtheHydraulicSystem(page4–31)forprecautionsandspecic
hydraulictestprocedures.
GeneralHydraulicSystemProblems
Problem
PossibleCauses
Thehydraulicuidisleakingfromthesystem.•Thetting(s),hose(s),ortube(s)arelooseordamaged.
•TheO-ring(s)orseal(s)aremissingordamaged.
Thehydraulicuidfoamsexcessivelycausing
uidleakagefromthehydraulictankbreather.
Note:Someaerationofthehydraulicuidonthismachine
isnormal.
•Thehydraulic-uidlevelinthehydraulictankislow.
•Thehydraulicsystemhasawrongtypeofuid.
•Oneofthepumpsuctionlineshasanairleak.
•Theincompatiblehydraulicuidsaremixedinthesystem.
•Thereiswaterinthehydraulicsystem.
Thehydraulicsystemoperateshot.•Thetransmissionpressureishighduetoload
ordraggingbrakes.
•Thehydraulic-uidlevelinthehydraulictank
islowortheinletlterislooseorclogged.
•Thehydraulicuidiscontaminatedortheuid
viscosityistoolight.
•Theoilcoolerisdamagedorplugged.Theoil
coolerairowisobstructed.
•Thetransmissionbypassvalve(s)isopenordamaged.
•Thegearpumpreliefvalveisstuckopen.
•Thetransmissioncheckvalveisnotseatingorisdamaged.
•Thechargepressureislow.
•Thetransmissionorwheelmotor(s)iswornordamaged.
Note:If1tractioncircuitcomponenthasinternalwearor
damage,itispossiblethattheothertractioncomponents
arealsodamaged.
TractionCircuitProblems
Problem
PossibleCauses
Thetractionresponseissluggish.
•Thetransmissionbypassvalve(s)isopenordamaged.
•Thebrakeisdraggingorbinding.
•Thetransmission-checkvalve,reliefvalve,and/or
ushingvalveisleaking.
•Thechargepressureislow.Thehydraulicuidisverycold.
•Thetransmissionorwheelmotor(s)iswornordamaged.
Note:If1tractioncircuitcomponenthasinternalwearor
damage,itispossiblethattheothertractioncomponents
arealsodamaged.
Neutralisdifculttond.
•Theexternalcontrollinkageisincorrectly
adjusted,disconnected,binding,ordamaged.
•Theoriceinthetransmission-checkvalve(s)isplugged.
•Thetransmissioniswornordamaged.
HydraulicSystem:Troubleshooting
Page4–28
Groundsmaster7210
16222SLRevE