Zoomlion RT60 Maintenance And Service Manual

Edition 2 Chapter 2 Page 2-5
Feb/2013 Troubleshooting
2.4 DERRICKING MECHANISM
Table 2-4
Part Problem Cause Remedy
Derricking Mechanism
Cylinder cannot extend
a) Main relief valve pressure
is set too low
b) Main valve leaks internally
c) Cylinder leaks internally
Adjust
Repair
Repair the seal ring
Cylinder cannot retract
a) Derricking-control balance
valve defective
b) Electrical system defective
Repair or replace
Repair
Cylinder retracts
automatically during
operation (will not hold its
position)
a) Cylinder leaks internally
b) Derricking-control balance
valve defective
Repair
Repair
Cylinder vibrates when
the boom is lowered
a) The right joystick moves to
the neutral position too
quickly
b) Opening pressure of the
derricking-control balance
valve is not constant.
c) Blockage in the
derricking-control balance
valve core
d) Blockage in the
derricking-control main
valve core
Move the joystick to
the neutral position
slowly
Examine the
accumulator of pilot
control valve block
for functional work
Clean or replace the
valve core
Clean or replace the
valve core

Zoomlion RT60 Specifications

General

Brand	Zoomlion
Model	RT60
Category	Construction Equipment
Language	English