Method Of Using Troubleshooting Chart - Komatsu WA250-6 Shop Manual

500 Troubleshooting of hydraulic and mechanical system (H-mode)

Method of using troubleshooting chart

Method of using troubleshooting chart
This troubleshooting chart determines the location from the problem occurring on the machine and catego-
rizes the problem under one of the main components, such as the steering system or work equipment
hydraulic system. Use the following procedure to carry out accurate troubleshooting swiftly.
Step 1. Ask operator questions
The questions to ask the operator are given
q
under the problem. If the answer to the ques-
tion matches the content given, the cause
g i v e n a f t e r t h e a r r o w i s t h e p r o b a b l e
cause.Keeping the content of the questions in
mind, read the matrix and proceed with Step 2
and Step 3 to pinpoint the correct cause.
Example: Steering does not turn
Ask the operator and check the following points.
Did the problem suddenly start?
q
Related equipment broken
o
Was the steering wheel heavy before?
q
Wear of related parts, defective seal
o
Step 2. Checks before troubleshooting
Before measuring the oil pressure or starting
q
the troubleshooting, confirm the checks before
starting items, check for leakage of oil, or for
loose bolts. This will prevent wasting time
when troubleshooting. The items given under
"Checks before troubleshooting" are checks
that are particularly important to make about
the condition of the machine before starting the
actual troubleshooting.
Example: Checks before starting troubleshoot-
ing
Is oil level and type of oil in hydraulic tank cor-
q
rect?
Is there any oil leakage from steering valve or
q
demand valve?
Is steering linkage adjusted properly?
q
WA250, 250PZ-6
Step 3. Method of reading matrix
1. Operate the machine when carrying out trou-
bleshooting of the items in the Diagnosis col-
umn. If any problems occur as the result of the
troubleshooting, put a check against the item.
a When carrying out the troubleshooting,
check the easier items first. It is not neces-
sary to follow the number order.
[Example]
No.
Diagnosis
Steering does not turn in both directions (left
1
and right)
Steering turns only in one direction (left or
2
right)
Steering is heavy when turned in both direc-
3
tions (left and right)
Steering wheel is heavy in one direction (left
4
or right)
5 Work equipment moves
2. Find the matching cause in the Cause column.
In the same way as in Step 2), if a problem is
found, the Q marks on the same line for the
troubleshooting item are the causes. (In Diag-
nosis item 2 in the same diagram below the
cause is (c) or (e).)
When there is one Q mark:
Carry out troubleshooting for the other items
marked with Q in the same Cause column to
ch ec k if the p ro b le m oc cu rs, the n ma ke
repairs.
When there are two Q marks:
Go to Step 3) to narrow down the cause.
SEN03849-00
1
Remedys
3
40-500