Groundsmaster 4100 --D/4110--D Hydraulic SystemPage 4 -- 63
Procedure for Lift/Lower Circuit Relief Pressure
Test
NOTE: Before attempting to check or adjust lift/lower
circuit relief pressure, make sure that counterbalance
pressure is correctly adjusted (see Counterbalance
Pressure Test in this section).
1. Make sure hydraulic oil is at normal operating tem-
perature by operating the machine under load for
approximately ten (10) minutes. Make sure the hydrau-
lic tank is full.
2. Parkmachineonalevelsurfacewiththecuttingdeck
loweredandoff.Makesureengineis offandtheparking
brake is engaged.
3. Remove controller cover to gain access to lift/lower
manifold (Fig. 45).
CAUTION
Prevent personal injury and/or damage to equip-
ment. Read all WARNINGS, CAUTIONS and Pre-
cautions for Hydraulic Testing at the beginning
of this section.
4. Connect a 5,000 PSI (345 bar) pressure gauge to
test port G1 on lift/lower manifold (Fig. 46).
5. After installing pressure gauge, start engineand run
at idle speed. Check for hydraulic leakage at pressure
gauge location and correct before proceeding with test.
6. Sitontheseatandmovethrottlesoengineisrunning
at high idle speed (2870 RPM).
7. Whilesitting ontheseat, depress therearofthecen-
ter lift switch to fully raise t he cutting deck. Momentarily
hold the switch with the deck fully raised while looking
at the gauge.
GAUGE READING TO BE approximately 2500 PSI
(172 bar).
8. Release the lift switch,stoptheengineandrecord
test results.
9. If specification is not met,clean or adjust reliefvalve
(RV1)inlift/lower control manifold. Relief valve (RV1)is
locatedonthetopsideofthelift/lowermanifold(Fig.46).
SeeAdjustControlManifold Relief Valvesin theAdjust-
ments section of this chapter for the valve adjustment
procedure. Recheck relief valve pressure setting after
adjustment.
10.Ifreliefvalveadjustmentdoesnotchangereliefpres-
sure, check for restriction in pump intake line, lift cylin-
der(s) internal leakage or gear pump damage.
11.When testing is completed, disconnect pressure
gauge from test port. Install controller cover.
1. Controller cover
2. Screw (2 used)
3. Flat washer (2 used)
4. U--nut (2 used)
Figure 45
FRONT
RIGHT
2
3
1
4
1. Lift/lower manifold
2. Test port G1
3. Relief valve RV1
Figure 46
1
2
3
Hydraulic
System
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