Braking information
Look after your RV trailer brake system and it will look after you
When discussing RV trailer brakes, it is difficult not to include the brake control—which is a very important function in the system. These two separate components safely reduce trailer speed at the same time as the tow vehicle. If required, they can be applied directly to the trailer brakes independently by activating the manual lever on the brake control for testing or in abnormal braking situations.
Safety First: Make sure your brake controls are working properly before you embark on a trip. Since it is exposed to the elements, the breakaway switch (bottom) should be inspected for signs of corrosion.—photo by Reg DeYoung
If the system is set up and functioning properly, stopping will be easy and predictable. The tow vehicle brakes won't overheat and speed control will be maintained during many situations on the highway. As stated above, the abnormal situations—such as trailer sway caused by side winds or passing semi trucks—can be reduced by the manual operation of the brake control; however, this type of brake activation can become a safety issue if you are travelling on a wet or icy highway so be cautious during these road conditions.
There are basically two types of RV trailer brake systems: electric or surge brakes. The surge brake system is usually found on boat trailers. In fact, an ICBC brochure states: “Surge brakes are not allowed on RV trailers over 2800Kgs GVWR.” The surge brakes operate through an actuator that is attached to the A—frame of the trailer. This system is hydraulic and has its own master cylinder. When the tow vehicle brakes are applied, the trailer moves forward towards the tow vehicle and pushes a piston in the master cylinder which, in turn, supplies hydraulic pressure to the brake cylinders and applies the trailer brakes guided by the decreasing tow vehicle speed.
The RV electric brakes work much differently in that this system uses DC power originating at the 12 volt tow vehicle battery. The main component at the brakes is the brake magnet. When the magnet is energized by the brake controller mounted inside the tow vehicle, it moves toward the brake drum or, more specifically, the armature. It is this lateral movement and the pulling force by the brake armature that activates the brakes by a cam that pivots the brake linings or shoes toward the drum, which are positioned so that one shoe will move the other—hence, primary and secondary brake shoes.
When the brakes are released or de—energized, the current ceases to flow to the magnet, which releases the force at the armature and the return springs pull the shoes back away from the brake drum.
The maintenance of electric brakes involves three areas: inspection, cleaning and adjustment. If you are unable to do these procedures yourself, your local RV service centre will help you out. RV technicians will check the function of the magnets, visually inspect the brake linings for abnormal wear, check the magnets for signs of uneven wear or broken wires and inspect the drums and/or armatures for abnormal wear. They will also clean and lube specific areas of the components, followed by an adjustment to the brakes to ensure the proper amount of clearances between the shoe and drum are maintained (RV brakes do not self adjust automatically like tow vehicle brakes)
If you have your brakes serviced, don't be surprised if you are advised by the service manager to have your wheel bearings re—packed. In most cases, this is a requirement or, at least, beneficial in regards to preventive maintenance.
The brake controllers available in the early years were usually electric hydraulic but with the addition of ABS systems on today's tow vehicles, most of the devices installed now will be strictly electric and will be activated in two ways: a swinging pendulum or by use of a time—activated increase in power to the brake magnets.
All RV owners should familiarize themselves with the set—up procedures of their brake control to ensure the unit is working at its best on each and every trip. If you have the control installed at an RV service centre, always make sure the instructions have been placed in your tow vehicle. If you have purchased an RV and are offered an orientation, ask for a demonstration of the functions and set—up procedures for your type of brake control.
One of the components of the RV braking system that is often neglected is the breakaway switch located on the A—frame of your RV; this device is an important safety feature and since it is exposed to the elements, it can become corroded to a point where it will not function when you need it the most. The breakaway switch will lock or dynamite the trailer brakes if the RV separates from the tow vehicle while being towed—provided the switch, wiring and RV battery are in good working order. Also, always have the cable attached with an individual quick link and not simply attached to the safety chains. You can test this unit for proper function by pulling the pin and trying to move forward with the trailer plug removed, preferably on a gravel surface. The wheels should drag if it is working properly.
As with your tow vehicle, it is much better to make sure all the components in the RV braking system are working properly and as efficiently as possible so they will be there when you need them the most.
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