Toro Groundsmaster 4500-D Series Service Manual page 180

Procedure for Lift/Lower Circuit Relief Pressure Test (continued)
Hydraulic System: Testing
6. While remaining on the seat, depress rear of lift switch (raise) to allow
lift/lower circuit pressure to increase. Momentarily hold the switch with the lift
cylinders fully retracted while looking at the pressure gauge as the lift/lower
relief valve opens.
GAUGE READING TO BE approximately 110 bar (1600 PSI) higher than
measured lift/lower circuit pressure with no load from step 5 above (e.g. if
circuit no load pressure is 21 bar (300 PSI), lift/lower relief pressure should
be approximately 131 bar (1900 PSI)).
7. Release the lift switch and stop the engine. Record test results.
8. If specification is not met, adjust or clean relief valve located in the lift control
manifold (see Lift Control Manifold (page
A. If pressure is too high, adjust the relief valve (see
Relief Valves (page
B. If pressure is too low, check for restriction in gear pump intake line.
Check the lift cylinders for internal leakage. If pump intake line is not
restricted and lift cylinders are not leaking, adjust the relief valve (see
Adjust Control Manifold Relief Valves (page
C. If pressure is still too low after relief valve adjustment, pump P4 or lift
cylinder(s) should be suspected of wear or damage.
9. Lower and secure seat after testing is completed.
5–155)).
5–86)).
Page 5–78
Adjust Control Manifold
5–86)).
Groundsmaster ® 4500-D/4700-D
19245SL Rev A