12
JCT-4660 series Paving Breaker
Problem
Possible cause
Remedy
Severe air leakage.
(Note: Minimal escape of
air is often normal for air
tools.)
Leakage from air inlet swivel.
Change O-rings and check for
loosening of air inlet swivel nut.
Leakage from throttle valve area.
Check for wear of throttle valve
stem guide. Replace if needed.
Leakage from back head and
cylinder.
Check plug; change O-ring on
throttle valve. Also check for
foreign matter which may have
entered during assembly.
Excessive heat develops
in tool.
Improper lubrication.
Lubricate properly according to
instructions in this manual.
Worn internal parts.
Inspect and replace as needed.
Tool continues to operate
after releasing throttle
lever.
Throttle valve seat is damaged.
Replace valve seat.
Blockage in valve area.
Remove any foreign matter.
Steel tool is loose.
Steel shank does not match
retainer bushing.
Use steel with correct shank type.
Front head bushing is worn.
Replace bushing.
Steel retainer latch refuses
to catch.
Excessive wear of retainer.
Replace parts as needed.
Excessive wear of retainer
plunger and spring.
Replace parts as needed.
