JLG 4017 Service Manual - Manual (Page 50)

Boom
3.26 4017
5. Dropping chain, or jerky
boom extend or retract
functions.
1. Chain(s) tension not properly
adjusted.
2. Chain(s) stretched or binding.
3. Wear pads loose, contaminated,
excessively worn or damaged.
4. Contaminated, corroded or
rusted wear pad sliding
surfaces.
5. Extend/Retract hydraulic system
not operating properly.
6. Damaged boom section.
1. Adjust chain(s).
2. Replace chains as needed.
Refer to Section 3.5, “Boom
Section Separation
Adjustment.”
3. Replace wear pad. Refer to
Section 3.7.2, “Boom Wear Pad
Replacement.”
4. Remove contamination and/or
corrosion from wear pad sliding
surfaces and lubricate. If the
surfaces cannot be reconditioned,
replace the boom section(s).
5. Refer to Section 8.4, “Hydraulic
Circuits.”
6. Replace the damaged boom
section. Refer to Section 3.3,
“Boom Assembly Maintenance.”
6. Boom will not raise or lower. 1. Broken hydraulic hoses or tubes
and/or connection leaks.
2. Lift/Lower hydraulic system not
operating properly.
3. Faulty Lift cylinder.
4. Seized boom pivot pin bushing.
1. Locate break, replace hose(s)
or tube(s), tighten connections.
2. Refer to Section 8.4, “Hydraulic
Circuits.”
3. Repair cylinder. Refer toSection
8.8.1, “General Cylinder
Removal Instructions.”
4. Replace bushing.
7. Excessive Lift/Lower cylinder
pivot pin noise and/or wear.
1. Insufficient lubrication.
2. Worn self-aligning bushing(s).
1. Lubricate at regular intervals.
Refer to Section 2.5, “Service
and Maintenance Schedules.”
Replace worn pins as needed.
Refer to Section 8.8.1, “General
Cylinder Removal Instructions.”
2. Replace bushing(s) and
lubricate at regular intervals.
(Refer to appropriate owners
manual for lubrication points.)
Boom Troubleshooting (Continued)
Problem Cause Remedy