Sakai SW800 Series, Руководство по ремонту

Страница: 91 / 159

4-002
Precautions for Troubleshooting
1. Precautions for Troubleshooting
Park the machine on level ground. Make sure that the safety pins are engaged, wheels
chocked and parking brake applied.
When working with other workers, use hand signals authorized, and keep people not
concerned away from the work area.
If the radiator cap is carelessly removed from a hot engine, hot coolant will gush out to
cause a burn. Remove the cap only when the engine has been cooled off.
Exercise care not to touch hot parts or not to be caught in rotating parts.
When disconnecting electric wires, disconnect the battery negative (-) cable.
When taking off plugs or caps from units which are under pressure such as hydraulic,
water and air pressures, fit gauges after removing residual pressure.
• Troubleshooting is to determine the root cause of troubles, repair faulty parts as quickly as prac-
ticable, and prevent recurrence of the troubles.
• Important when conducting troubleshooting practice is of course to well understand the struc-
ture and function of machines to be handled. For effective troubleshooting, however, it is of
prime importance to have a clear picture of the trouble concerned by contacting the operator.
1. When a trouble has occurred, do not
attempt to disassemble blindly.
Disassembling in a hurry will invite disadvan-
tageous situations as described below:
• Parts which need not be disassembled
may be disassembled.
• Tracing the cause of trouble will become
more difficult.
These will cause increased service costs
because of wasteful service hours, spare
parts or expendables like oil or grease. To
make matters worse, such a careless prac-
tice will invite operator's (customer's) dis-
trust. For these reasons, sufficient advance
investigations and diagnosis in accordance
with troubleshooting procedures specified
are essential for efficient fault finding prac-
tices.
2. Questions to be addressed to the opera-
tor (customer) .
1) Are there any trouble other than the one
in question?
2) Was there any abnormal condition with
the machine before the trouble occurs?
3) Did the trouble occur suddenly without
signs of abnormal conditions in advance?
4) In what occasion did the trouble occur?
5) Has the machine been repaired before
the trouble occurs? If so, when has it
been repaired?
6) Did similar trouble occur in the past?
3. Before-diagnosis inspection
1) Perform daily inspections.
2) Perform other inspections required for
diagnosis.
4. Confirmation of trouble
Know the degree of the trouble. Determine
whether it is a trouble cause by improper
design etc. or the trouble was caused by
incorrect handling.
★
When making the trouble reccur in an
attempt to trace the source of the
trouble by putting the machine in
motion, use care not to cause more
damage to the machine.
5. Troubleshooting
From the results of items 2 to 4 above, nar-
row down the cause of the trouble, and pin-
point the source of the trouble by utilizing
the diagnosis flow chart.
★ The basic points of the diagnosis are:
1) Start from the simple portion.
2) Start from the portion having a high prob-
ability to solve the problem.
3) Investigate related matters.
6. Basic remedy for the trouble
Even if a trouble is rectified, it will develop
again if its cause is not determined. It is of
prime importance to trace the very cause of
the trouble.