Sakai SW800 Series, Shop Manual

Page: 148 / 159

4-405
Fault Finding for Hydraulic and Mechanical Systems
YES
NO
6
YES
NO
Is charge circuit
pressure in propul-
sion line as speci-
fied?
14
*See Standard Value
Chart.
7
YES
NO
Is charge circuit pres-
sure higher than per-
missible value with
F-R lever moved for-
ward and backward?
Is fault rectified if
charge relief valve
is disassembled
and cleaned?
15 YES
NO
Does charge pressure
return to normal with
ports (A, B) in front
motor blocked (unload-
er valve opened)?
16
Disconnect hoses from
ports A and B from the
front motor and con-
nect both ports directly.
plug hoses.
Possible cause Remedy
To ‘A’ on page
Rear wheel flushing valve
faulty.
• Clean and
adjust.
• Renew if
necessary.
Charge relief valve faulty.
Oil leakage at sliding portions
(such as piston) of front wheel
motor.
Internal leakage of brake
cylinder.
Steering pump faulty. Renew.
Leakage at sliding portions
(pistons of propulsion pump or
vibrator pump etc.).
Repair or renew
wire.
Pump servo valve or servo
linkage defective.
*See Standard Value
Chart.
• Clean and
adjust.
• Renew if
necessary.
Repair. Renew
if necessary.
Repair. Renew
if necessary.
Oil leakage at sliding portions
(such as piston) of rear wheel
motor.
Repair. Renew
if necessary.
Repair or renew
wire.
F-R lever linkage defective.
Repair or renew
wire.
Unloader valve lever in
incorrect position.
Set correctly.
Damaged splined portions in
coupling or pump shaft. Repair or renew
wire.
*1 Recheck the item enclosed by a dotted line.
*2 Due to difficulty in deciding checking
sequence, a ‘NO’ line on this page carries
two checking items.
• Generally, checking items with smaller refer-
ence number have higher probability.