One brake over adjusted

This RV belongs to my kids. An on the road check was sone to be sure it was not locked up, and the controller was backed way down. The shop repair and inspection were done only a couple miles from home. Just to be clear, I am more than familiar with electric brakes in all respects — repair, replace and adjust. The shop verdict is that the offending brake was seriously over adjusted. Yet, there had been no problem for 1500 miles, and the factory insists it was adjusted when new.. It appeared suddenly. Now everything is properly adjusted and it has been inspected. So the question is this: what would cause a non-self adjusting brake to suddenly become over adjusted? Dexter says it can't unless there is a brake "malfunction'". But they can't even suggest what that might be. Bad magnet? Intermittent short? These wheels and tires are on an in-cab monitor, so the temps will show if the problem returns. Its originally showed a slightly higher temp (5 or 6 degrees) but nothing dramatic. A passing motorist warned that the brake was smoking.

enahs wrote:
Dexter engineering says that since the brake can't over adjust itself, there must be a "malfunction" with the brake itself. But they are not suggesting what it might be and what we should look for!

So you had it “fixed” and presumably towed it home? Did you check the brake temps?
Or maybe I’m lost here….
FWIW, it is worth the cost of your “use” of the trailer to be able to do simple repairs, or in this case, adjustments, to keep you on the road doin your thing vs cutting a trip short or getting stranded or whatever.
I’m certain there is a YooToob tutorial on adjusting drum brakes. Requires only a screwdriver and a means to jack up a wheel. And a basic understanding of which way to adjust the star wheel manually.
Food for thought.

enahs wrote:

Roger10378 wrote:
Something is not right here. If the brakes were not adjusted right either at the factory are later they would not wait 1500 miles to overheat. Are you sure that you don't have a bearing problem?

I agree entirely. That's what bothers me. No sign of bearing failure. Bearings all checked and repacked. Brakes are apparently ok. Not clear why the problem occurred, which is bothersome. Dexter says once adjusted there is no way for the brake to become over adjusted on its own. We shall see.

Consider this, it is possible that the three OTHER brakes were UNDERADJUSTED from the factory, in other words the other three brakes were factory set too loose and were not providing much or no braking support leaving the only one set tighter to provide all of your braking.. That most certainly can cause the tighter brake to overheat and smoke..

Although in all of this, you should have noticed something wrong almost immediately.. I have had a wire break off at one of the backing plates several times over the yrs.. Each time I noticed the trailer giving a tug or pull in the opposite direction of the broken wire (IE wire broke on drivers side but pulled to the passenger side)..

Best to just make sure everything is adjusted correctly, wiring is good and move on.. Life is too short to fret about a few "what ifs"..

Dexter engineering says that since the brake can't over adjust itself, there must be a "malfunction" with the brake itself. But they are not suggesting what it might be and what we should look for!

Only on RV net, an out of adjustment brake on a new trailer results in someone saying upgrade to disk brakes! ROFLMAO

Roger10378 wrote:
Something is not right here. If the brakes were not adjusted right either at the factory are later they would not wait 1500 miles to overheat. Are you sure that you don't have a bearing problem?

I agree entirely. That's what bothers me. No sign of bearing failure. Bearings all checked and repacked. Brakes are apparently ok. Not clear why the problem occurred, which is bothersome. Dexter says once adjusted there is no way for the brake to become over adjusted on its own. We shall see.

Cummins12V98 wrote:
Gdetrailer said: "Changing to disc brakes is a pretty extreme drastic uneeded and expensive change which also has some very expensive pitfalls. Disc brakes adds additional maintenance with needing to check brake fluid level and periodic replacement of said fluid. Unless you run DOT5 (silicone) brake fluid (which has it's own problems), it will go bad over time from drawing moisture from the air while the trailer sits still.. Adds in a very expensive EOH pump to the trailer which is a failure point and some brake controllers will rebel with EOH pumps."

A lot of negativity for no reason. Expensive pitfalls? Not hardly.

Everyone that has gone to Disks has said I wish I had done it sooner.

I would love disk braks, just not the 6000 buck bill that comes with them. would be nice if it was a option for them from the factry where you pay the difference so 2000 fo the disk brake option. or somthing like that.

Steve

Gdetrailer wrote:
It IS possible IF the brake drum is "out of round" which is also possible..

Check the offending brake drum turns evenly by hand all the way around.. If any time the brake drum gets hard to turn (catch/stop) you might have a brake drum that is not perfectly round on the inside..

The out of round condition can allow the adjuster take up extra slack where the drum is further from the brake shoes.. As the drum turns to where the drum surface is closer to the brake shoes it gets too tight.. Heating up the brake shoes and drum surface..

A small amount of out of round can exist, but if it too extreme it can cause issues.

that would be pretty rare to find unless you overheated your brakes pretty hard. the last step they do when making the drums is to throw them on a laith and turn the braking surface so it should be true.

Gdetrailer said: "Changing to disc brakes is a pretty extreme drastic uneeded and expensive change which also has some very expensive pitfalls. Disc brakes adds additional maintenance with needing to check brake fluid level and periodic replacement of said fluid. Unless you run DOT5 (silicone) brake fluid (which has it's own problems), it will go bad over time from drawing moisture from the air while the trailer sits still.. Adds in a very expensive EOH pump to the trailer which is a failure point and some brake controllers will rebel with EOH pumps."

A lot of negativity for no reason. Expensive pitfalls? Not hardly.

Everyone that has gone to Disks has said I wish I had done it sooner.

Something is not right here. If the brakes were not adjusted right either at the factory are later they would not wait 1500 miles to overheat. Are you sure that you don't have a bearing problem?