jcb JS300 Service Manual page 1036

Relief Valve
Symptom Possible Cause
a Motor does not run or 1 Relief valve not closing fully:
rotation speed is slow.
i Foreign matter clogging components.
ii Spring broken.
2 The cracking pressure of relief valve is low.
i Spring is deformed.
ii Poppet orifice is clogged.
b Motor does not stop 1 Relief valve not closing fully.
or stops slowly.
i Foreign matter clogging components.
ii Spring broken.
2 Refer to a2.
c Motor does not run or 1 Shockless function does not work.
rotation speed is slow.
i Foreign matter in piston section.
ii Spring broken.
iii Relief valve pressure set too high.
F-59
K Relief Valve ( T F-59)
9813/5100-1
Section F - Transmission
Fault Finding
Remedy
Completely remove foreign matter, repair
damaged part and reassemble after
cleaning. Renew if damage or leakage is
excessive.
Renew the spring. Completely remove
foreign matter, repair any damage and
reassemble after cleaning. Renew if
damage or leakage is excessive.
Renew relief valve sub-assembly.
After cleaning, reassemble.
Completely remove foreign matter, repair
damaged part(s) and reassemble after
cleaning. Renew if damage or leakage is
excessive.
Renew the spring. Completely remove
foreign matter, repair any damage and
reassemble after cleaning. Renew if
damage or leakage is excessive.
K Relief Valve ( T F-59)
Refer to a2.
Completely remove foreign matter, repair
damaged part and reassemble after
cleaning. Renew if damage or leakage is
excessive.
Renew the spring. Completely remove
foreign matter, repair any damage and
reassemble after cleaning. Renew if
damage or leakage is excessive.
Adjust the relief valve set pressure.
Transmission
F-59