jcb JS200 Service Manual page 459

Section F
5 - 3
Fault Finding (continued)
Relief Valve
Fault
1. Motor does not
run or rotation
speed is slow.
2. Motor does not
stop or stops
slowly.
3. Excessive shock
when travel is
stopped.
9803/6400
Transmission
*
Motor/Gearbox
Possible cause
1. Relief valve closing incorrectly.
1) Foreign matter is clogging
components.
2) Spring is broken
2. The cracking pressure of relief valve
is low.
1) Spring is deformed
2) Poppet orifice is clogged
1. Relief valve closing incorrectly.
1) Foreign matter is clogging
components.
2) Spring is broken.
2. The cracking pressure of relief valve
is low.
1) Spring is deformed.
2) Poppet orifice is clogged.
1. Shockless function does not work.
1) Foreign matter caught up in
shockless piston section.
2) Spring is deformed.
3) Relief pressure set too high.
Countermeasure or remedy
Completely remove foreign matter, repair
damaged part and reassemble after
cleaning. Replace if damage or leakage is
excessive.
Replace the spring. Completely remove
foreign matter, repair the damaged part and
reassemble after cleaning. Replace if
damage or leakage is excessive.
Replace relief valve sub assembly.
After cleaning, reassemble.
Completely remove foreign matter, repair
damaged part and reassemble after
cleaning. Replace if damage or leakage is
excessive.
Replace the spring. Completely remove
foreign matter, repair the damaged part and
reassemble after cleaning. Replace if
damage or leakage is excessive.
Replace relief valve sub assembly.
After cleaning, reassemble.
Completely remove foreign matter, repair
damaged part and reassemble after
cleaning. Replace if damage or leakage is
excessive.
Replace the spring. Completely remove
foreign matter, repair the damaged part and
reassemble after cleaning. Replace if
damage or leakage is excessive. Readjust
the relief valve set pressure.
Section F
5 - 3
Issue 2*