Electric trailer brake dragging. Questions.

[wh500special 2,160]

I towed one of my trailers about 40 miles the other day.  When I got home, I noticed the passenger side wheel was hot.   It wasn’t “oh my god” hot, but it was clearly not right.  

 

Figured the bearings or brakes might need attention.  

 

Jacked it up and there was a lot of drag on the wheel.  Could barely rotate it by hand.  Aha, brake is dragging!

 

pulled the wheel and drum.  The drum was pretty hard to get off.  Took a lot of cussing and swearing.

 

Noticed the rear brake shoe - the secondary one that engages when in reverse - was not returning to its home position.  Everything in the brake backing plate and mechanism is

spotless.  Just some brake dust.  No rust or corrosion.  Basically, looks new in there.  

 

Went online and to YouTube to make sure everything looks right.   Yep, everything appears just how all the pictures show it.  Orientation right.   Magnet on bottom.  Big shoe in the rear.  Small shoe on the front.  Drum looks good.  Magnet looks good.  Check.  Check.  Check. Check.  Check.  Check.  

 

Tapping the shoe, I can get it to go back to its resting position.  But when actuated with the actuator arm, it sticks in the activated/out position.  

 

So i cleaned up what I could and lightly greased all the points where the shoe either pivots or rubs on something.  It seemed to free up and only stuck if I stroked it as far as it would go.   

 

Put it all back together.  Adjusted the adjuster star until it was

just about dragging then backed it off.  Checked other side and confirmed approx equal adjustment.  

 

Went for a short test drive.   All seemed fine.  

 

Got home and it’s hot again.  Jacked up the wheel and sure enough, it’s dragging again. 

 

I can replace the whole brake assembly easily and cheaply enough, but wondering what I’m missing here.  

 

I guess a spring could be weak. 

 

I Welcome suggestions.  

 

Steve

 

ps- probably should mention I repacked the bearings while I was

in there.  They were perfect.   After test ride could definitely tell heat was in the drum, not the hub. 

 

Edited July 9, 2019 by wh500special
Had to get my bearings.

[Cvans 1,009]

I got tired of fighting brake problems like yours and just replaced them. Haven't had to touch them since. 

 

[rmaynard 15,427]

I too used to have that problem on a Coachman travel trailer years ago. Nothing I did seemed to correct the issue. It was always the same side. Other side worked fine. So I replace the whole set up. I seem to remember it was a reasonably cheap fix. 

[squonk 41,024]

Brakes activate by the electro magnet. I have seen on other applications over time, the magnet will stay partially magnetized. Perhaps that's what's happening.

[wh500special 2,160]

Thanks guys.

 

I think I'll just replace the whole thing.  Brake assemblies are cheap, even the Dexter namebrand ones.  Not worth putting much troubleshooting into this.

 

Steve

[nylyon-(Admin) 7,268]

 I agree, I replaced all 4 last year on my camper, no sense messing with it.

 

[RandyLittrell 3,877]

I haven't used the brakes on my car trailer for years, I figure I will have to do the same thing!! 

 

 

 

Randy

[1995 520H+96+97 937]

Do the brakes drag with the breakaway battery disconnected?

[wh500special 2,160]

The breakaway seems to work as it's supposed to.  I didn't disconnect it to check, but it's not affecting the other side and I don't think I had power to the brakes when I was messing with them.

 

I ordered new backing plate assemblies yesterday afternoon.  Decided to try the self adjusting type this time.  Hopefully they come quickly so I can get this thing back road worthy.

 

After towing a trailer the first time that had good working brakes, I'll never go back to not having them when possible.  Order of magnitude safer than not having them.  The trailer that these are on technically (legally) doesn't require them, but the difference in stopping is day and night.  Cheap insurance against running into a busload of kindergartners.

 

Steve

[wh500special 2,160]

Closing the loop...

 

The new brakes came already.  Had no idea that etrailer.com was located right here in my back yard.  That's handy.

 

I bought the Dexter self-adjusting set.  Figured whether they were technically better or not than the cheaper ones, they were made in the USA instead of by someone in a far away place so were worth the small price bump.

 

I put them on last night.  Back in business!  Still a little fine tuning to do since I ran out of daylight before I could get my wiring neatly managed, but safe to tow again.

 

The old brakes seemed like they were well made. But they do look a little different than these.  These look to have a heavier return spring mounted at a angle that doesn't change as the shoe moves.  I don't know if that makes a functional difference, but I feel they could be more reliable since the spring exerts linear force on the shoes instead of degrading a bit for small displacements as the shoe gets closer to its resting position.  On the old brakes, when the shoe is fully retracted it doesn't really look like there is any tension on the spring.  It might look different when under the drum and things are adjusted.

 

Thanks for the suggestions.

 

Steve