Service Manual

27
Using a systematic approach makes hydraulic
troubleshooting easy. By following a process
which narrows down the possible causes, a
problem can be pinpointed and confirmed.
Step
1 : Ask the Operator
Step
2: Study the Available Information
Step
3: Inspect the Machine
Step
4: Operate the Machine to Verify Problem
Step
5: List the Possible Causes
Step 6: Test Possible Causes
Step 1 : Ask The Operator
A detailed problem description is a valuable
diagnostic tool during troubleshooting.
Has there been oil
loss from the system?
What type of terrain (slope) was the product
used on?
How was the unit being used?
How warm was the fluid?
What type of maintenance has been performed?
Did anything unusual happen before the
problem occurred?
Answers to these questions should be recorded
on the work order.
Step 2: Study The Available Information
Review the technical information which applies
to the hydraulic system you are working with.
Flow diagrams will show which types of
components are involved in the system.
Can the problem be related to a particular circuit
or part of a circuit? Does the problem seem to
be pressure related? Does the problem seem to
be related to oil flow? What components are
controlling these conditions?
Be sure to check for Service Bulletins which
may apply to this system.
Example Complaint
Lift system doesn’t work. Can not
get the deck to raise.
Problem Description
Hasn’t noticed oil
loss.
Used on fairly flat yard for mowing
only.
Same operation
if hydro cold or
warm.
Use
5 seasons - never serviced
Circuit Involves
Charge Pump
Spool Valve
Lift Cylinder
Filter
Lines
& Fittings
Control Linkage for
spool valve
Productivity Series