Dexter Axle Electric Brakes

The easiest way to troubleshoot the brakes is with an ampmeter - 3 amps maximum per brake magnet. If they're not able to draw that much power, they're not working. I agree with pulling the drums to have a look to see if everything still looks good. Don't bother replacing parts, buy a new backing plate with all new parts - they're not very expensive. https://www.etrailer.com/dept-pg-Trailer_Brakes-sf-Electric_Drum_Brakes.aspx

Your magnets are probably severly worn along with the shoes being glazed and/or cracked. I would just order new backing plate assemblies so everything gets replaced. Regardless of what you had, go for the new forward adjusting units. They work far better.

Defiantly pull the drums.

You may have got things hot enough that the grease seal has failed and you may find grease everywhere.

Cummins12V98 wrote:

jbrack wrote:

Cummins12V98 wrote:
Your brakes were not adjusted properly, you would have known it the instant the brake away popped if they were!!!

Which brings me back to my original question...these brakes are self-adjusting...what does that process look like? Is it automatic, or do I need to do something in the way I drive to make it happen?

They simply don't work!!! Do it the old fashion way.

jbrack asked a valid question.

It deserves a better explanation than "to do it the old fashion way".

Jbrack, self adjusting drum brakes are nothing new, been around for many yrs on automobiles which used drum brakes. So you can check out how the automobile self adjusting drum brakes to understand trailer axle self adjusting drum brakes. Understanding that how the brakes are actuated is different (hydraulic for auto and electromagnet for trailer axle).

You can go HERE for a simple overview of an automobile self adjusting brake works.

Now to get to Cummins comment, you have to realize that anyone that may have driven a vehicle which had drums on all four corners will have a lot less "excitement" when it comes to the highly touted "self adjusting" trailer axle brakes..

Self adjusting drum brakes on autos do not have a stellar track record for being 100% reliable and often would fail to adjust properly in unison on at least one drum..

Was a lot of fun when that happened to be on one of the front drums on your steering and you stepped on the brakes and resulted in catapulting you off the road or across the road into apposing traffic at the most inopportune time...

Adjusters over time tend to get stuck from lack of movement, this often was caused by the star wheel screw threads rusting, dirt from grease on the threads. Sometimes even the star wheel would end up having a few of the points worn off if stuck..

Often the wire which pulls the pawl across the star wheel rust off, break or jamb rendering the adjuster useless. Drums which are too far out of round (too much "runout") can also prevent the adjusters from working properly.

For trailer axle brakes you do not have to do anything special, they are designed to adjust in forward and reverse.

With auto drum brakes you simply had to backup for a short distance then apply the brake hard.

For the little amount of miles towing a RV vs what you would drive an automobile I can't find any real reason to intentionally buy auto adjusting trailer brakes.. Autos often see 12,000-20,000 miles per yr but your trailer most likely will be far less than that and a lot less wear on the brakes.

I rarely have to adjust my trailer brakes and finally replaced the original brakes on my 30+ yr old TT due to a cracked shoe.. I am always puzzled how folks burn through the trailer brakes in only a couple of yrs..

I see the self adjusting trailer brake feature as an expensive gimmick sold to folks who are afraid of drum brakes, do not understand the brakes are just too lazy to do some basic and simple maintenance.

I have found that the new forward adjusting brakes on my TT work great. I check them at the end of the season but no further adj is needed.

jbrack wrote:

Cummins12V98 wrote:
Your brakes were not adjusted properly, you would have known it the instant the brake away popped if they were!!!

Which brings me back to my original question...these brakes are self-adjusting...what does that process look like? Is it automatic, or do I need to do something in the way I drive to make it happen?

That is a pretty new trailer. Were the self adjusting brakes properly adjusted (manually) when new? After initial manual adjustment, the auto adjust should do it's job.

I agree, full on emergency braking should be quite obvious, if they were properly adjusted.

Jerry

jbrack wrote:

Cummins12V98 wrote:
Your brakes were not adjusted properly, you would have known it the instant the brake away popped if they were!!!

Which brings me back to my original question...these brakes are self-adjusting...what does that process look like? Is it automatic, or do I need to do something in the way I drive to make it happen?

They simply don't work!!! Do it the old fashion way.

The way they adjust depends on the model. Some auto adj when you apply the brakes going backwards and some of the newest ones do so moving Forward.

If they are self adjusting the will adjust every time you use the brakes if they need it. Something must not have been very well adjusted or you would not have been able to drive a 1/2 mile before realizing what had happened. You need to take a good look and see what has happened like others have said.

To answer your question, the brakes only adjust when the wheels are turning and you step on the brake pedal. But if the linings are severely out of adjustment it can take many stops to adjust them out. In your case I would also suggest having the drums pulled and the brakes and wiring inspected and then the brakes manually adjusted.