How to Adjust RV Trailer Brakes
You can do it yourself!
Trailer brakes should be adjusted at least once a year, more often depending on the miles traveled, the severity of downhill grades, and the amount of stop-and-go traffic encountered. This is a chore that most people with average mechanical skills can handle. You will need a brake adjusting tool (available at most auto parts stores), a hydraulic jack capable of safely lifting the trailer, and jack stands to secure the trailer in the raised position.
The following steps are a guide to properly adjusting your trailer brakes by adjusting the star wheel, which sets the brake shoe to brake drum clearance. This adjustment is important – as the brake shoes wear down, the clearance increases. The actuating mechanism must travel further to effectively apply the brakes, and a point can be reached where the mechanism is no longer able to do so.
Step-by-Step Adjustment Procedure
- Park the trailer on firm, level ground.
- Block the trailer tires on the opposite side securely with wheel chocks so that no forward or rearward movement is possible.
- Jack up the trailer following the manufacturer's instructions.
- Secure the trailer on jack stands of adequate capacity at both front and rear.
- At the back of the wheel on the brake backing plate, locate the small rubber plug near the bottom. Pry out this plug to access the star wheel adjuster.
- Some trailers have a drop-axle suspension system that covers part of this adjusting hole, making it tighter to work. Patience will win out if you keep at it.
- Insert the brake adjuster tool and maneuver it so that the tip engages with the teeth on the star wheel (which looks like a gear with exposed teeth). On most trailers, pulling down on the tool handle levers against the bottom of the hole and turns the star wheel up (as viewed from behind the wheel). A flashlight helps locate the star wheel inside the backing plate.
- Turn the adjuster until the brake locks up and you can no longer rotate the wheel by hand. This centers the brake shoes properly inside the brake drum.
- Back off the star wheel 8 to 10 clicks (or as specified by the manufacturer). The wheel should now spin freely with no heavy drag. A slight scraping sound from the shoes touching the drum is normal as the wheel turns.
- Repeat this procedure for all remaining wheels.
Congratulations, you have successfully adjusted your own trailer brakes!
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