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60 - 3
Fault Finding
Trouble
Causes
Solutions
Set pressure is high
Back pressure on port T.
Adjust the port T back pressure.
Small hole in the Poppet
4
is
Dismantle and clean valve,
blocked.
reassemble.
Set pressure is low
Spring setting
19
Replace the spring or add shim.
Small hole in the Poppet
4
is
Dismantle and clean valve,
blocked.
reassemble.
Does not relieve pressure
Malfunction of the poppet
4
Dismantle and clean valve,
repair/replace if any fault identified.
The leakage value from the ACC
Damage to the check seat section
8
Dismantle and clean valve,
port P1 or P2 is more than normal.
or contamination.
Check the bearing, repair/replace.
Does not return to neutral.
Malfunction of the solenoid valve
2
Refer to solenoid valve section.
Malfunction of the spool
18
Dismantle and clean valve,
repair/replace if any fault identified.
Spring
9
defective
Replace the spring.
Does not return to neutral.
Malfunction of the spool
16
Dismantle and clean valve,
repair/replace if any fault identified.
Spring
7
defective
Replace the spring.
During Operation
Set pressure is low
Low inlet pressure
Adjust the relief valve.
Malfunction of the spool
13
Dismantle and clean valve,
repair/replace if any fault identified.
Spring
21
defective
Replace the spring or add shim
1
.
Set pressure is high
Malfunction of the spool
13
Dismantle and clean valve,
repair/replace if any fault identified.
Back pressure at port T
Adjust the port T back pressure.
Malfunction of the solenoid valve
2
Refer to solenoid valve section.
During Locking
No inlet pressure
Malfunction of the solenoid valve
2
Refer to solenoid valve section.
The leakage value is more
Damage to the seat section
Dismantle and clean valve,
than normal.
or contamination.
Check the bearing, repair/replace.
Defective operation
Low voltage
Ensure correct voltage.
Malfunction of the solenoid coil
20
Replace coil
Malfunction of the spools
23
and
24
Dismantle and clean valve,
repair/replace if any fault identified.
Spring
6
defective
Replace the spring.
Section E
Hydraulics
9803/6020
Section E
60 - 3
Issue 1
Multiple Valve
Relief V
alve
Check
V
alve
Shut of
f
V
alve 1
Shut of
f
V
alve 2
Shuttle
V
alve
Solenoid
V
alve
Pr
essur
e Reducing V
alve 2
Summary of Contents for JS70
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