Brake Dragging… Need Help

[dbawden]

I’m running out of ideas. Have self adjusting breaks. Worked fine for 5000 miles and then started having problems. I had one brake dragging. I jacked up one side, applied the brake. The problem wheel always showed more friction then the other. Thinking it was a wiring problem I swapped the wiring to see if I could transfer the problem to the other wheel but nada. Same wheel had a bigger brake bite. I thought that proves the problem must be the magnet or a short in the wiring inside the problem wheel. Took it apart. No obvious wiring issue so I replaced the entire brake with a new one. Worked fine for a few days and then began locking up again.

Any suggestions would be appreciated.

[Iowa Dave]

When you had it apart did you look at the friction and pivot points where the actuator arm crosses over? They usually have some grease on them when they are new .

Secondly you might have the drum checked to make sure it’s either not warped out of round.
With a high/ low spot maybe the shoe is hanging up. We used to turn those drums on a brake lathe when they were thicker. I needed an old drum for a project a while back. I went to my brake guy. He gave me a brand new drum for an old Camaro a guy was fixing up. The shop owner told me the drum came in so out of round they couldn’t use it.

Finally the big spring needs enough tension to pull the shoes back once the magnet releases. A bad spring is possible.

Just spitballing here. Good luck
Iowa Dave

[SRS]

Iowa Dave may be on to something. If you replaced the backing plate assembly with new shoes, magnet, etc. but didn't replace the drum, the problem may be a badly warped drum.

[dbawden]

Good suggestion. I didn’t replace the drum. I’ll eliminate that as a source next. Thanks so much. I wouldn’t have though of that.

[felix2]

I have the same issue with one wheel. Had it broken down and inspected, with no noticeable issues, and it was fine for a while. Then it happened again and I reduced the controller gain and it went away for more than a season. It just happened again last trip and my gain is down to 1.5 to make it stop. I think I’ll have the drum roundness checked as you suggested - that one tire is getting bald spots from skidding!

[edlynnrich]

I have the same problem with one wheel. I put a flat spot on the tire when I had to do an emergency stop when a deer jumped in front of us. Thanks Dave for the trouble shooting tips.

[Iowa Dave]

When we had the 2010 I never had a problem with the Natalie’s hanging up. The spring after we got the trailer I checked the shoes. The “opposite” was occurring in that three shoes were worn evenly and one was like new. Following the two wires back to where they connected to the “ pair of power supply wires, I found that one butt splice had been crimped short of the brake wire being pushed into the crimping sleeve. So it was touching and was a little corroded and when I tugged on it, it pulled right out. And I knew why there was very little wear on that shoe. Wasn’t getting electricity. I reported this shortcoming on this forum and had several responses that indicated this had been their problem too. So an inexperienced installer at rhe trailer frame manufacturer was no doubt part of the problem.

Point being there are a lot of moving parts and some not moving that make up the system. For me, I’ve found problems over the years on any number of systems by just looking at them and thinking a process through. Sometimes that’s what it takes. You will get it. Never hurts to have another set of eyes and questioning mind.

I was in my office years ago, fingers laced behind my neck, looking out into an empty park in the dead of winter. A visitor came in and asked me what I was doing. I told him “I’m thinking.”
His response “Must be nice to get paid just to think.” Made me sad to realize how shallow and impaired this guy was.
I just said “Pays pretty well.”

Best of luck
Iowa Dave

[dbawden]

Thanks. I like the way you think.

[dbawden]

Update…so I backed off the adjustment on the brake, replaced the trailer plug wiring and junction box. No change. Pulled both hubs off on one side and switched them to see if one was out of round.. Nope. Same slamming brake problem on same wheel. I’m ready to just cut the blue brake wire to that wheel and run with three brakes. If I ever find out the root cause I’ll post it here.

[Viajante]

Please do post when the problem is solved. As I understand your trouble shooting you replaced the brake assembly. You swapped wires with another wheel, you swapped hubs with another wheel. In swapping hubs you were changing out the brakes, including the drum and the bearings, and still no help on the problem wheel. A spindle problem?...doesn't seem right. A faulty breakaway switch leaking some voltage?...to one wheel? ...I can't see that either. So I'm no help but I applaud your efforts. Good luck.

[Iowa Dave]

How about the spring that keeps Tension on the brake adjuster, when you flip the adjuster does it take some effort as opposed to being real easy to turn? Maybe the brake is adjusting up too tight on its own? Are they self adjusters or manual? Did you grease the pivot points on the lever that actuates the shoes out and pulls them back?
Iowa Dave

[Rossue]

Originally Posted by dbawden

Update…so I backed off the adjustment on the brake, replaced the trailer plug wiring and junction box. No change. Pulled both hubs off on one side and switched them to see if one was out of round.. Nope. Same slamming brake problem on same wheel. I’m ready to just cut the blue brake wire to that wheel and run with three brakes. If I ever find out the root cause I’ll post it here.

Hi Dave- been following this and was hoping to see you fixed. You backed off the adjustment, however we had a similar experience when trailer was new and LSS it was out of adjustment- too loose. In that situation the shoe slaps against the drum and causes lockup. We ruined a tire in a short period of time due to it.

[dbawden]

Hi Ross,

I’m thinking along those lines right now. Note..at low brake setting "1" slight drag develops in good wheel with no drag on problem brake. When set to "2" the bad brake SLAMS locked even though the brake is adjusted very loose.

I adjusted the grabbing brake for a bit of drag and will drive it around tomorrow to get the brake unit centered on the hub. (I’m not sure how it does that though.)

Hi Dave,

Yes there is good tension on the spring and yes they are self adjusters. If the problem persists after tomorrow’s trial run, I’ll pull the hub again and check the internal mechanisms more closely. I’ll also insure the ground to the frame on the problem wheel is cleaned up.

Thanks all for suggestions. Like most problems, the solution will be obvious when it arrives.

[dbawden]

I’d like to say I found the smoking gun but…

After doing all of the above, I pulled both wheel hubs and switched them back to their original location, cleaned off a bit of grease on the problem wheel pad that showed up from all of the swapping, and took the trailer for a test drive. I set the brake tension to 6.0 and had NO issues. I’ll take the trailer on a 300 mile test in a few weeks and see if the fix (whatever it was) holds. If there is no further problem I’ll chock this one up to perseverance rather then effective problem solving. Thanks all…until the next time.

[Rossue]

Originally Posted by dbawden

I’d like to say I found the smoking gun but…

After doing all of the above,

Did that include adjustment? I went through an awful lot with ours too when it was new. Dexter paid for a new backing plate, bought me a tire and it finally came down to the wheel brake(right front) being too loose in adjustment. Was a bit embarrassing; sometimes the simplest solution is the best one- Occam's razor.

[dbawden]

Hi Ross,

That included adjusting. After reassembling and the trailer still jacked up I set the adjustment to 1…both wheels had slight drag, set to 2 and the problem wheel almost didn’t turn. Frustrated I just took it for a spin to see if it would lock up with a brake setting of 2, then 5 then 6. All seemed well so I just threw up my hands, thought this is nuts, and drove home. If the problem recurs after a couple of hundred miles (like last time), I’ll take it into a shop or call a preacher to lay hands on it and cast out the demons.