7 hydraulic brake coupler, Troubleshooting, Hydraulic brake coupler -10 – JLG T350 Service Manual User Manual
Page 46: Troubleshooting -10, Surge brake troubleshooting -10

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