Troubleshooting; General Hydraulic System Problems - Toro GroundsmasterR 4300-D Service Manual

Troubleshooting

The cause of an improperly functioning hydraulic sys-
tem is best diagnosed with the use of proper testing
equipment and a thorough understanding of the com-
plete hydraulic system.
A hydraulic system with an excessive increase in heat
or noise has a potential for failure. Should either of these
conditions be noticed, immediately stop the machine,
turn off the engine, locate the cause of the trouble and
correct it before allowing the machine to be used again.
Continued use of an improperly functioning hydraulic
system could lead to extensive hydraulic component
damage.

General Hydraulic System Problems

Problem
Hydraulic oil leaks from machine
Foaming hydraulic fluid
Hydraulic system operates hot
Hydraulic System
The charts that follow contain information to assist in
troubleshooting. There may possibly be more than one
cause for a machine malfunction.
Review the hydraulic schematic and information on hy-
draulic system operation in the Hydraulic Flow Dia-
grams section of this chapter. This information will be
useful during the hydraulic troubleshooting process.
Refer to the Testing section of this chapter for precau-
tions and specific hydraulic test procedures.
Possible Causes
Fitting(s), hose(s) or tube(s) is (are) loose or damaged.
O--ring(s) or seal(s) is (are) missing or damaged.
Oil level in hydraulic reservoir is low.
Hydraulic system has wrong kind of oil.
Pump suction line has an air leak.
Traction system pressure is high due to excessive load or brake
dragging or binding.
Oil level in hydraulic reservoir is low.
Hydraulic oil is contaminated or too light.
Engine speed is too low.
Fan speed is low dues to a loose or damaged belt.
Oil cooler is damaged or plugged. Air flow through oil cooler is
obstructed.
Oil filter is plugged.
Piston (traction) pump bypass valve is loosened or is damaged.
Charge pressure is low.
Piston (traction) pump check valve is not seating or is damaged.
Wheel motor(s) and/or piston (traction) pump are worn or damaged
(NOTE: If a traction circuit component has internal wear or damage, it
is possible that other traction circuit components are also damaged).
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