Toro Groundsmaster
4000?D Service Manual page 74

PRELIMINARY – For Toro Distributor and Toro Company use only.
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 units
lowered and off. Make sure engine is off and the parking
brake is engaged.
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.
28). Route gauge hose to allow seat to be safely low-
ered.
4. Sit on the seat and start the engine. Move throttle to
full speed (2870 RPM).
5. While sitting on the seat, pull lift lever back to raise
the cutting units. Momentarily hold the lever with the lift
cylinder at full extension while looking at the gauge.
GAUGE READING TO BE 1500 to 1600 PSI.
6. Stop the engine. If pressure is too high, adjust relief
valve in lift control valve by rotating counterclockwise
(Figure 29). 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.
Hydraulic System
CAUTION
2
1. Lift circuit port
1. Control valve assembly
2. Relief valve assembly
3. Washers
Page 4 − 40
1
Figure 28
2. Hydraulic reservoir cap
2
3
4
5
1
Figure 29
4. Spring
5. Poppet
Groundsmaster 4000−D