5-6
5
OVERALL MACHINE
TROUBLESHOOTING
Boom, bucket, slew and arm fail to move or are too slow.
1 Check the gear pump
Faulty
•
Repair or replace the gear
pump
•
Replace the coupling
Normal
2 Check the fuse
Faulty
Replace the fuse
Normal
3 Check the limit switch
Faulty
Adjust
or replace the limit
switch
Normal
4
Check
the lever lock sole-
noid valve
Faulty
Repair
or replace the lever
lock solenoid valve
Normal
5
Check
the pilot relief
valve
Faulty
Repair
or replace the pilot re-
lief valve
Normal
6 Check the pilot valve
Faulty
Repair
or replace the pilot
valve
1. Check the gear pump
Check the hydraulic pump (1) which supplies hydraulic
pressure to the pilot valve.
• The inspection procedure is the same as for the pis-
ton.
“5-3”
Also, check the line filter for clogging, and clean it as
necessary.