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

Troubleshooting

General Hydraulic System Problems

Problem
The hydraulic fluid is leaking from the system.
The hydraulic fluid foams excessively causing fluid leakage
from the hydraulic tank breather.
Note: Some aeration of the hydraulic fluid on this machine
is normal. This aeration (foaming) may be more noticeable
after initial filling of hydraulic tank.
The hydraulic system operates hot.
Groundsmaster ® 4300-D
16226SL Rev C
The following chart contains suggestions that can be used to solve performance
issues specific to the hydraulic system. The suggestions are not all-inclusive.
There can be more than 1 cause for a machine malfunction.
Review the hydraulic schematic found in Appendix A—Foldout Drawings and
information on the hydraulic system operation in the
(page 4–16). This information will be useful during the hydraulic troubleshooting
process.
Refer to Testing the Hydraulic System (page 4–44)
hydraulic test procedures.
• The fitting(s), hose(s), or tube(s) are loose or damaged.
• The O-ring(s) or seal(s) are missing or damaged.
• The hydraulic-fluid level in the hydraulic tank is low.
• The hydraulic system has a wrong type of fluid.
• One of the pump suction lines has an air leak.
• Incompatible hydraulic fluids are mixed in the system.
• There is water in the hydraulic system.
• The traction system pressure is high due to load or dragging
brakes.
• The hydraulic-fluid level in the hydraulic tank is low or the
inlet filter is loose or clogged.
• The hydraulic fluid is contaminated or the fluid viscosity
is too light.
• The oil cooler is damaged or plugged.
• The oil cooler air flow is obstructed.
• The piston (traction) pump bypass valve is open or
damaged.
• The gear pump relief valve is stuck open.
• The piston (traction) pump check valve is not seating or
is damaged.
• The charge pressure is low.
• The piston (traction) pump or wheel motor(s) is worn or
damaged.
• Engine RPM is too low.
Note: If 1 traction circuit component has internal wear or
damage, it is possible that the other traction components
are also damaged.
Page 4–39
Hydraulic Flow Diagrams
for precautions and specific
Possible Causes
Hydraulic System: Troubleshooting