Toro 30411, Service Manual

Page: 81 / 262

Groundsmaster 4100--D Hydraulic System Page 4 -- 39
Procedure for Lift/Lower Circuit Relief Pressure
Test
NOTE: Before attempting to check or adjust lift pres-
sure, make sure that counterbalance pressure is cor-
rectly adjusted.
1. Make sure hydraulic oil is at normal operating tem-
perature by operating the machine for approximately 10
minutes. Make sure the hydraulic tank is full.
2. Park machine on a level surface with the cutting
decks lowered and off. Make sure engine is off and the
parking brake is engaged. Raise seat.
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.
3. Raise seat to gain access to hydraulic test fitting.
Connect a 5,000 PSI gauge to lift circuit test port (Fig.
32). Route gauge hose to allow seat to be safely low-
ered.
4. After installing pressure gauge, start engine and run
at idle speed. Check for hydraulic leakage and correct
before proceeding with test.
5. Sit on the seat and operate the engine at full speed
(2730 + 30 RPM) .
6. While sitting on the seat, pull lift lever back to raise
the cutting decks. Momentarily hold the lever with the lift
cylinder fully retracted (decks fully raised) while looking
at the gauge.
GAUGE READING TO BE 2500 to 2550 PSI.
7. Record test results.
8. Stop the engine. If pressure is too high, adjust relief
valve in lift control valve by rotating counterclockwise
(Figure 33). If pressure is too low, check for restriction
in pump intake line. Check the lift cylinder for internal
leakage. If cylinder is not leaking, adjust the relief valve
by rotating clockwise. If pressure is still too low, pump or
lift cylinder(s) should be suspected of wear, damage or
inefficiency.
9. Disconnect pressure gauge from test port.
1. Lift circuit port 2. Hydraulic reservoir cap
Figure 32
2
1
1. Control valve assembly
2. Relief valve assembly
3. Washers
4. Spring
5. Poppet
Figure 33
2
3
1
4
5
Hydraulic System