Lawn Mower User Manual

Groundsmaster 4100--D Hydraulic SystemPage 4 -- 35
Procedure for Traction Circuit Relief Pressure Test
1. Make sure hydraulic oil is at normal operating tem-
peraturebyoperatingthemachineforapproximately10
minutes. Make sure the hydraulic tank is full.
CAUTION
Movemachinetoanopenarea,awayfrompeople
and obstructions.
2. Drive machine to an open area, lower cutting deck,
turn the engine off and engage the parking brake.
CAUTION
Prevent personal injuryand/or damageto equip-
ment. Read all WARNINGS, CAUTIONS and Pre-
cautions for Hydraulic Testing at the beginning
of this section.
3. Connecta10,000PSI(700bar)gaugetotractioncir-
cuit testport for functiontobe checked (Forwardor Re-
verse: Fig. 22 or 23).
4. After installingpressure gauge, startengine andrun
at idle speed. Check for hydraulic leakage and correct
before proceeding with test.
5. Operate the engine at full speed (2870 RPM).Make
sure that transport/4WD switch is in the transport posi-
tion.
6. Sitonseat,applybrakesfullyandslowlydepressthe
traction pedal in the appropriate direction. While pu-
shingtractionpedal,lookatpressurereadingongauge:
GAUGE READING TO BE:
Forward: 3750 to 4250 PSI (259 to 293 bar)
Reverse: 4750 to 5250 PSI (328 to 362 bar)
7. Release tractionpedaland stopengine.Record test
results.
8. If traction pressure is too low, inspect traction pump
reliefvalves(Fig.24).Cleanorreplacevalvesasneces-
sary.Thesecartridgetypevalvesarefactorysetandare
notadjustable.Ifreliefvalvesareingoodcondition,trac-
tionpumporwheelmotorsshouldbesuspectedofwear
and inefficiency.
NOTE: Seal leakage across pilot directional valves
PD1 and PD2 in 4WD manifold can also cause low for-
ward traction pressure with reverse pressure meeting
specifications.
9. When testing is completed, disconnect pressure
gauge from test port.
1. Forward traction port 2. LH front tire
Figure 22
1
2
1. Reverse traction port 2. RH front tire
Figure 23
1
2
1. Forward relief valve
2. Reverse relief valve
3. Traction pump
Figure 24
FRONT
RIGHT
1
2
3
Hydraulic
System