Troubleshooting; Hydraulic System Problems - Toro Groundsmaster 4500-D Service Manual

Troubleshooting

The charts that follow contain information to assist in hy-
draulic system troubleshooting. There may possibly be
more than one cause for a machine malfunction.
General Hydraulic System Problems
Problem
Hydraulic system operates hot.
NOTE: An indication that the hy-
draulic system is operating at exces-
sive temperatures would be frequent
reversing of the cooling fan and a
normal engine coolant temperature.
Hydraulic oil in reservoir foams.
Hydraulic oil leak(s).
Groundsmaster 4500--D/4700--D
Refer to the Testing section of this Chapter for precau-
tions and specific testing procedures.
Possible Cause
Engine RPM is too low.
Hydraulic reservoir oil level is low.
Hydraulic oil is contaminated or the wrong type.
Brakes are applied or sticking.
Piston pump bypass valve(s) is open or damaged.
Cooling system is not operating properly.
Charge pressure is low.
Engine cooling fan circuit is malfunctioning (see Engine Cooling Fan
Circuit Problems in this section).
Traction circuit pressure is incorrect.
Pump(s) or motor(s) are damaged.
Hydraulic reservoir oil level is low.
Wrong type of oil is in the hydraulic system.
Air is leaking in suction line.
Fitting(s), hose or tube loose or damaged.
Missing or damaged O-ring in fitting.
Page 4 - - 37 Hydraulic System