Trailer Brakes


I searched around for some info on electric trailer brakes and found very little on the subject. So here’s a scenario for you tow veterans out there: I’ve got a 2005 20’ Haulmark enclosed (electric brakes on both axles). Bought used and could not verify at time of purchase if the brakes worked or not. I bought an electric brake controller and have verified that it is working correctly (good signal at 7 way - and it is adjusted properly). Despite this, trailer does not brake (at all as far as I can tell).

So I bring it to a local trailer shop and they tell me it needs 800 smackers worth of new backing plates, repacking the bearings and new hubs. Despite the fact that a set of RA’1’s cost 650, $800 for trailer brakes has me incensed. Anyone out there now if this is right? Any idea at parts costs and the labor involved in DIY?


I bought my small open trailer as part of a package deal with my car 6yrs ago. I congratulated myself on getting the trailer as part of the package. A couple months later I took the trailer in to a trailer shop to get caught up on maintenance. To my surprise and dismay I ended up having to replace everything you described plus tires.

I suppose that this should all be do-able DIY, but it’s not something I’ve done before so I can’t help on the subject.

#3 is a good source for parts, at least to get an idea of the costs. Generally, trailer parts are pretty cheap. I’ve never replaced brakes, but hubs/bearings aren’t that bad, there is probably a tutorial on the site for that stuff too.


I also use The brakes really aren’t that complicated.


I should have also mentioned that I paid more than you did. 2yrs later I had to buy new tires. 2yrs later new tires, wheels and axles. The axles turned out to be a little bowed which was making me burn thru tires rapidly. Next time I’m going to buy a new trailer, not a used one.


I purchased a whole axle with brakes for less than $800 from somewhere before, and that includes freight shipping. Only issue was installing it by myself. Required some welding on my part, but nothing scary.

The issue is measuring everything to ensure you are getting exactly the right axle as a replacement. There are hundreds of different sizes with different types of brakes.


Most trailer brakes are electrically actuated drum brakes. Being that your tralier is an '05 from a decent manufacture, I bet the axles are fine.

What the trailer people told you I believe is a bunch of BS if they say you need to replace your bearings to fix the brakes. Here is where I would start.

Wiring on trailers is 9 times out of 10 bad. They just don’t take the time to do it right and cleanly, thus it fails after a few years. Check that you are getting power to each wheel cylinder. Easy way is to have one person manually actuate the brakes on and off via the controller while other person is listening to each wheel for clicking. It will be easy to hear if they are working. Harder but better way is get under the trailer, chase the wires, and check for power and ground.

To check wheel bearings, drive the thing around (loaded would be better), stop, and touch every wheel hub. If they are hot (like can’t keep your hand on it hot), you have bad bearings and need to repace them ASAP. If they are warm but you can keep you hand on it, then they either need the grease repacked or the axle nut is too tight. I check this everytime I stop to full the truck with gas while pulling. Replacing bearings is pretty easy for some one with average mechanical skills.

I can tell you much, much more, but it be too long for this forum. Shoot me an email if you want.

barkerdm86 at gmail dot com


If you do need new brakes, you can buy pre-loaded backing plates you simply bolt-on with everything ready to go. Several guys who repair trailers told me this is usually cheaper than buying parts peacemeal, and that way you know you’ve licked the problem with all new stuff. Most of this stuff is pretty standard and your local trailer dealer or RV shop will probably have them in stock.


I have to agree with the repair folks. While you can get individual parts for electric trailer brakes, I have found it to be more cost effective to replace the backing plate assembly and drum. The electromagnet puck that activates the brakes wears down, as does the surface of the drum it rides on. Enough wear there and the brakes won’t work right. Assuming water or dirt contamination or a seal failure isn’t a cause, by the time the wheel bearings need to be replaced the brakes do to, and vice versa. A new drum usually comes with bearings.


+1 for terrible quality trailer wiring. Crimp on plastic splice connectors have no business being exposed to the weather.


What are some better solutions for connectors on a trailer? My trailer wiring sucks.


The perma-seal connectors seem to work well, marine parts type stores or your bass-pro fishing buddy should be able to hook you up as well. They are dipping thier trailers in the water all the time.