Service Manual

TestingtheTractionCircuit–PistonPump/HydrostatFlowand
ReliefPressure(5610-D)
g216148
Figure120
Thehydrostatowtestisthethirdinaseriesoftestsrecommendedtodetermine
thetractioncircuitperformance.ThistestcomparesuidowatNoLoadwith
uidowUnderLoad.Adropinowunderloadofmorethan12%indicates
aninternalleakormalfunctioningreliefvalveinthepistonpump/hydrostat.A
wornhydrostatormalfunctioningreliefvalveislessefcient.Eventually,enough
uidbypasswillcausetheunittostallunderheavyloadconditions.Continued
operationcangenerateexcessiveheat,causedamagetosealsandother
componentsinthehydraulicsystem,andaffectoverallmachineperformance.
SpecialEquipmentRequired:
•Pressuregauge
•Flowmeterwithpressuregaugethathasatleasta114L/minute(30
gallons/minute)capacity
TestProcedure
1.Warmoilaftertestequipmentisconnectedtopreventtechnicianfrom
workingonahotmachine—applicabletotestswhenpossible(anytestthat
requiresanopenun-pluged/cappedline(casedraintests)wouldnotapply
andoilshouldbewarmedbeforedisconnectingthelines).
HydraulicSystem:TestingtheHydraulicSystem
Page6–110
Reelmaster
®
5410/5510/5610Series
15216SLRevD