Groundsmaster 4500--D/4700--D Hydraulic SystemPage 4 -- 37
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.
Refer to the Testing section of this Chapter for precau-
tions and specific testing procedures.
General Hydraulic System Problems
Problem Possible Cause
Hydraulic system operates hot.
NOTE: An indication that the h y-
draulic system is operating at exces-
sive temperatures would be frequent
reversing of the cooling fan and a
normal engine coolant temperature.
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)ormotor(s)aredamaged.
Hydraulic oil in reservoir foams. Hydraulic reservoir oil level is low.
Wrong type of oil is in the hydraulic system.
Air is leaking in suction line.
Hydraulic oil leak(s). Fitting(s), hose or tube loose or damaged.
Missing or damaged O-ring in fitting.
Hydraulic
System