JLG 150HAX Service Manual - Manual (Page 135)

SECTION 6 - SCHEMATICS
3120817 – JLG Lift – 6-7
.
BOOM SWING SYSTEM
No response to swing control.
Hydraulic system oil low. Replenish oil as necessary.
Swing control lever not functioning. Repair or replace swing lever.
Restricted or broken supply line on valve bank or
hydraulic pump. Clean or replace line.
Control valve not functioning properly. Repair or replace valve.
Swing motor not functioning properly. Repair or replace motor.
Swing brake not releasing. Repair or replace brake.
Torque hub not functioning properly. Repair or replace torque hub.
Foreign objects(s) wedged between torque hub
pinion and swing gear. Remove objects, check for
damage, and repair or replace
component(s) as required.
Sheared shaft on swing motor/brake. Repair or replace motor/brake.
.Boom will not swing outside of
drive/steer wheels.
Axles not extended and locked. Extend and lock axles.
Boom will swing in only one direction.
Restricted or broken hydraulic line or fitting. Clean, repair, or replace line or fitting.
Control valve not functioning properly. Repair or replace valve.
Foreign object(s) wedged between torque hub
pinion and swing gear. Remove object(s), check for damage and repair
or replace component(s) as required.
Swing control lever not functioning properly. Repair or replace swing control lever.
Brake shuttle valve defective. Replace shuttle valve.
Boom swings erratically in either direction.
Hydraulic system oil low. Replenish oil as necessary.
Lack of lubricant on swing gear or torque hub pin-
ion. Lubricate as required.
(See Lubrication Chart.)
Swing motor not functioning properly. Repair or replace swing control lever.
Worn or broken teeth on swing gear or torque
hub pinion. Replace gear(s) as required.
Swing brake not functioning properly. Repair or replace swing brake.
Swing brake shuttle valve defective. Repair or replace valve.
Table 6-2.Boom Assembly - Troubleshooting
TROUBLE PROBABLE CAUSE REMEDY