Lift Circuit Working Pressure And Relief Pressure - Toro Groundsmaster 580-D Service Manual

TEST NO. 4: Lift Circuit Working Pressure and Relief Pressure
WORKING Pressure Test
1. Connect a 5,000 psi gauge to the LIFT test port.
a. On machines with serial number below
250000000, the LIFT test port is located on the out-
side of the control console (Fig. 12).
b. On machines with serial number above
250000000, the LIFT test port is located underneath
the center of the machine (Fig. 12A).
2. Operate the machine while monitoring gauge.
TESTER READING TO BE:
375 to 2,000 PSI (S/N below 240000000).
375 to 2,500 PSI (S/N between 240000001 and
240999999).
500 to 2,625 PSI (S/N above 250000000).
3. If working pressure is too high or too low, perform re-
lief pressure test.
RELIEF Pressure Test
1. Hydraulic oil must be at operating temperature.
2. Connect a 5,000 psi gauge to the LIFT test port.
a. On machines with serial number below
250000000, the LIFT test port is located on the out-
side of the control console (Fig. 12).
b. On machines with serial number above
250000000, the LIFT test port is located underneath
the center of the machine (Fig. 12A).
3. Start the engine and adjust throttle so engine speed
is 2,500 RPM.
4. Engage the lift control lever into the LIFT position.
Momentarily hold lever in engaged position after full cyl-
inder extension and read gauge.
TESTER READING TO BE:
1,500 to 2,000 PSI (S/N below 240000000).
2,000 to 2,500 PSI (S/N between 240000001 and
240999999).
2,125 to 2,625 PSI (S/N above 250000000).
Groundsmaster 580--D
NOTE: Always set counterbalance pressure to correct
amount before attempting to adjust lift relief pressure
(see TEST 5).
5. If pressure is too high, inspect relief valve in lift control
valve. If necessary, adjust relief valve by removing the
required shim(s). If pressure is too low, check for restric-
tion in pump intake line. Check lift cylinder(s) for internal
leakage. If cylinder is not leaking, clean relief valve, and
adjust if necessary by adding required shim(s). If pres-
sure is still too low, repair or replace steering/lift pump.
1
NOTE: Deck drive Test Ports
on older models are
also on this panel.
1. Lift test port (S/N below 250000000)
2. Traction forward test port
1. Lift test port (S/N above 250000000)
Rev. F
Page 4 - -
27
2
Figure 12
1
Figure 12A
Testing