Electric trailer brakes may experience wear on their brake linings and drums that
increases wear over time, creating an gap. To address this problem, simply adjust
the controller as necessary to change it accordingly.
Gain settings tell a brake controller how much power to send to electromagnets
within a trailer brake assembly, thus improving braking performance. A lower gain
setting yields better results in terms of improved braking.
How to Adjust
Your trailer needs a screwdriver, jack and some way of securing it before beginning
this task. By taking some time and patience you should be able to set your electric
brakes so they contact the drum almost instantly, thus relieving stress from your
tow vehicle’s brakes while improving overall braking performance.
Most trailer brakes are controlled via a controller located within the cab of your
towing vehicle, with this control designed to activate them when one of their pedals
is depressed. Sometimes calibration may be necessary in order to achieve optimal results from this controller.
First, test and adjust the gain (which controls how much voltage is sent to the trailer
brakes when your vehicle’s brakes are applied). Next, set the sensitivity, which
controls how aggressively the brake controller activates them – accelerate to 25mph
before applying brakes – then test how aggressively they activate. If they stop too
slowly increase sensitivity; otherwise if abruptly reduce it.
Tools
Electric trailer brakes utilize electromagnets and a control unit to provide effective
braking when called for by their towing vehicle’s driver. By relying on electrical
signals from their control unit, electromagnets within each brake are powered from
within to accentuate or squeeze trailer brake pads for effective stopping action.
No matter if your trailer features electric or manual brakes, having them properly
adjusted is vital to reduce wear and tear on both vehicle brakes and ensure that it stops when needed.
Checking and adjusting trailer brakes every 3,000 miles is highly recommended, and
can be accomplished easily using the right tools. This guide walks through this
process step-by-step, from jacking up the trailer, accessing its brakes and using an
adjustment tool, all the way through testing for tire lockup. Specifically you’ll need
wrench, screwdriver and an adjustable trailer brake tool (such as brake spoon or
spoon tool); additionally a rubber adjusting cap or “star wheel” may be found
underneath your trailer brake drum to complete this task.
Preparation
Electric brakes are activated using an electromagnet that attracts an armature
surface of the hub when exposed to a small current, such as from your tow vehicle
or breakaway battery. For optimal performance, it is crucial that trailer brakes be in
sync with their respective tow vehicle controller. This will ensure they do not
become oversensitive causing them to skid, nor overlight putting undue strain on its brakes.
First, ensure your tow vehicle’s handbrake is engaged and that the trailer cannot
move by blocking one tire or using jack stands. Next, jack up and place the trailer on
a level surface; remove its adjuster dust cap before using a screwdriver to locate
and unscrew its star adjustment wheel; you may require a flashlight if working in dim lighting conditions.
Final Words
Electric current from the tow vehicle powers brake controller, 7 pin trailer connector
and magnet on actuating arm to activate brakes in either direction of rotation.
Some factory and aftermarket controllers come equipped with variable voltage
output settings that enable drivers to set their gain or braking force according to
weather and trailer weight conditions. These proportional-style controllers are often
included as part of manufacturer tow vehicle packages.
All this electric current generates heat in the actuating arm and magnet surfaces it
makes contact with, such as those located near the drum. Therefore, it’s crucial that
wire used is large enough; Dexter has noted in their FAQ’s that it takes between 100
to 150 stops for brake shoes to fully burnish (become effective brakes).
Furthermore, to minimize interference it would be wise to keep brake grounds
separate from lighting grounds in order to prevent problems from developing
between them.