Adjusting RV Trailer Brakes
You can do-it-yourself!
RV trailer brake adjustment is a job that most people with average mechanical skills should be able to
RV trailer brakes should be adjusted at least once a year, more often depending on the miles
travelled, the severity of the downhill grades, and the amount of stop and go traffic that is encountered.
You will need a brake adjusting tool, available at most tool supply stores, a jack capable of
safely lifting the trailer, and a jack stand to hold the trailer in the jacked position.
The following steps are a guide to properly adjusting your trailer brakes. What this entails is the
adjustment of the star wheel which in turn 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 so.
Park the trailer on firm and level ground.
Block the trailer tires on the opposite side securely so that no forward or rearward movement is
Jack up the trailer following the manufacturers instructions.
Secure the trailer on jack stands of adequate capacity front and rear.
At the back of the wheel, on the brake backing plate, there is a small rubber plug near the bottom
of the backing plate. Pry out this plug to give access to the star wheel adjuster.
Some trailers have a drop axle suspension system and the axle covers most of this adjusting hole
making it difficult to use the brake tool. Patience will win out in the end if you keep at it.
Insert the brake adjuster tool and maneuver it so that the tool engages with the teeth in the star
wheel. The star wheel looks like a gear with exposed teeth on the perimeter. On most trailers you would pull down
on the tool handle which levers on the bottom of the hole and turns the star wheel up (as you are looking at it
from the back of the wheel. Just to make it more difficult, the star wheel is located well inside and some
maneuvering is required - a flashlight will help to locate the starwheel.
Turn the adjuster until the brake locks up, i.e. you can no longer rotate the wheel by hand. This
centers the brake shoes on the brake drum so that they are in the correct position.
Now back off the star wheel 8 to 10 clicks or as specified by the manufacturer. The wheel should
spin freely with no apparent drag to slow it down. A slight scraping noise is normal as the wheel turns.
Repeat this procedure for all the wheels.
Congratulations, you have successfully adjusted your own trailer brakes ... that wasn't so bad, was
Brakes worn out?
It can be more cost effective to replace the entire backing plate assembly than to replace the brake shoes
alone. A new backing plate assembly will give you a new magnet as well and all new springs, etc. Also, they
are easier to install ... simply remove the four bolts holding it on and disconnect two wires. See in the RV Parts Store