JLG G12-55A Service Manual - Manual (Page 68)

Boom
3-32 G10-55A, G12-55A
3.14 TROUBLESHOOTING
This section provides an easy reference guide covering
the most common problems that occur during operation
of the boom.
Problem Cause Remedy
1. Boom will not extend or
retract
1. Broken hydraulic hose(s)
or tube(s) and/or
connections leaking.
1. Locate break, replace hose(s)
or tube(s), tighten connections.
2. Extend/retract hydraulic system
not operating properly.
2. Refer to Section 8.4, “Hydraulic
Circuits.”
3. Faulty extend/retract cylinder. 3. Repair cylinder, Refer to Section
8.8, “Hydraulic Cylinders.”
2. Boom shifts to right or left
when extending.
1. Boom side wear pads
improperly shimmed or worn.
1. Shim wear pads to correct gap.
Replace wear pads as needed.
Refer to Section 3.9, “Boom
Wear Pads.”
3. Excessive boom pivot pin
noise and/or wear.
1. Insufficient lubrication. 1. Lubricate at regular intervals.
Refer to Section 2.7,
“Lubrication Schedules.”
Replace worn pins as needed.
2. Worn bearing(s). 2. Replace bearing(s) and
lubricate at regular intervals.
Refer to Section 2.7,
“Lubrication Schedules.”
4. Excessive Compensation
cylinder pivot pin noise and/
or wear.
1. Insufficient lubrication. 1. Lubricate at regular intervals.
Refer to Section 2.7,
“Lubrication Schedules.”
Replace worn pins as needed.
2. Worn bushing(s). 2. Replace bushing(s) and
lubricate at regular intervals.