Attachment Circuit Cannot Be Changed - Komatsu PC200-8M0 Shop Manual

SEN06139-00
H-28 Attachment circuit cannot be changed
For machines with provision for attachment
q
Failure Attachment circuit is not changed
q When attachment installation specification is employed, service circuit is changed as follows ac-
cording to selected working mode.
Related infor- 1) ATT mode: Service circuit is changed to double acting circuit and safety valve is set to low pres-
mation sure.
2) B mode: Service circuit is changed to single acting circuit and safety valve is set to high pressure.
q
Safety valve set pressure on only B port side is changed; that on A port side is kept low.
MalfunctionofATT return
1
selector solenoid valve
Probable
causes and cri-
teria
Malfunction of ATT return
2
selector valve
Malfunction of service valve
3
(safety valve)
40
40-500
500 Troubleshooting of hydraulic and mechanical system (H-mode)
Cause
a Be ready with engine stopped, then troubleshoot with engine
high idle.
ATT return selector valve may have malfunction. Check it.
Safety valve (port B side) of service valve may malfunction. Check
it.
H-28 Attachment circuit cannot be changed
Criteria and troubleshooting procedure
Working mode
ATT mode
B mode
PC200, 200LC, 220, 220LC-8M0
ATT return selector solenoid
valve output pressure
0 MPa
2
{0 kg/cm }
Approx. 2.9 MPa
2
{Approx. 30 kg/cm }