JLG T350 Service Manual - Manual (Page 46)

SECTION 3 - CHASSIS & TURNTABLE
3-10 – JLG Lift – 3121198
3.7 HYDRAULIC BRAKE COUPLER
Troubleshooting
IF ANY OF THE FOLLOWING CONDITIONS DEVELOP, TRAILER
MUST NOT BE USED UNTIL PROPER CORRECTIVE ACTION IS
TAKEN.
Table 3-4. Surge Brake Troubleshooting
Symptom Cause Solution
Squeaking, Clatter, or Chucking Lack of Hitch Ball Lubrication Lubricate with conventional automotive grease or commer-
cial lubricant made for hitch balls
Binding Linkage & Pivots on Brake Actuator Oil linkage & pivots on brake actuator
Loose Hitch Ball Inspect hitch and tighten
Loose Hitch Inspect hitch and tighten
Actuator loose on trailer frame Inspect brake actuator and tighten
Hitch ball worn or too small Replace
Overheated Brakes Replace wheel bearing
Broken Brake Drum(s) Replace brake drum(s) & check brake shoes
Low Brake fluid level Fill & bleed brakes
Worn out shock absorber Replace
Partial application of breakaway cable Fully release breakaway cable
Brakes improperly adjusted Check brakes
Broken brake return spring Replace return spring
Seized actuator master cylinder Replace/rebuild actuator master cylinder
Worn out brake shoes Replace brake shoes and check brake drums
Leaky wheel cylinders Replace/rebuild wheel cylinders and replace brake shoes.
Clean drums and other hardware.
Release handle does not close easily Oversized ball Check ball size
Ball not fully inserted into socket Check for proper ball size. Check to see if tongue jack is fully
retracted. Hold release handle open when inserting ball.
Foreign material in actuator socket Clean and lubricate
Brake Overheating, Side Pull, Brakes do
not Operate, Poor Brake Performance Only one brake is applying Check brake adjustment
Leaking wheel cylinder Check and replace wheel cylinder and bleed brakes
Seized wheel cylinder piston Check and rebuild/replace wheel cylinder and bleed system.
Foreign Material in Brake Unit Clean thoroughly
Low hydraulic fluid level Fill and bleed brakes
Bent shoulder bolt Replace
Bent push rod in the shock absorber Replace shock absorber
Damaged socket assembly Replace actuator
Broken/Pinched brake lines Replace
Brake actuator frame damaged Replace actuator
Worn brake shoe(s) Replace brake shoe(s)
Towing Vehicle Shaking Back and Forth Worn vehicle suspension Replace shock absorber
Hitch not secure Tighten all bolts and nuts
Under-sized hitch ball Replace with proper size