Electric Brake Randomly Locks Up

[Sherwolfe]

Having an issue with my left front trailer brake. It will intermittently lock up but only when the speed is under or around 20mph. So I have pulled the wheel down, looked at the brake and all appears normal. No grease, contact magnet looks good and clean. I also checked the ground wire at the frame as well as a good look at them around the axle, including the inside of the brake drum.

I've traced the wires as much as I can and can not seem to find any loose or broken or worn wires. This lock up only occurs on the left front wheel, and is very intermittent which makes this even more frustrating. My gain for my Ford controller is set at 6 and none of the other tires are locking up. At higher speeds all seems to work just fine.

For those with Ford trucks, I did just recently have my trailer brake controller updated with the new software, well actually when Ford checked it they told me mine already had the updated software. So now i'm out of ideas on what might be causing this issue. Any troubleshooting ideas would be appreciated.

[Ramtop]

I had that problem this past summer right after we bought our 5th wheel which was used. We headed out on a trip and it kept locking up so I finally backed it off enough so it wouldn’t bother. When I tore it apart afterwards, I found that the backing plate had a slight tweak in it causing the shoes to not move freely. I replaced it with a new assembly and that took care of the problem.

[ChuckS]

I do not believe the issue is with your Trucks integrated brake control ..

All four RV brakes are wired in parallel.. The signal that is sent to one brake manet is the same as the other 3.. ( voltage and amp )..

I would pull that hub back off and check:
1. Measure the resistance of that brake magnet ( 3.2 ohms ) typical
2. Use a straight edge and measure across the magnet surface for overall flatness of the magnet face
3. Check the two wires leading into the coil on the magnet for any evidence of damage, looseness, etc
4. Check the operation of the self adjust mechanism on that brake ( the brakes adjust themselves Only when brakes are applied and moving forward)

[Sherwolfe]

Originally Posted by Ramtop

I had that problem this past summer right after we bought our 5th wheel which was used. We headed out on a trip and it kept locking up so I finally backed it off enough so it wouldn’t bother. When I tore it apart afterwards, I found that the backing plate had a slight tweak in it causing the shoes to not move freely. I replaced it with a new assembly and that took care of the problem.

Thanks for the input. Will have to check on this.

[Sherwolfe]

Originally Posted by ChuckS

I do not believe the issue is with your Trucks integrated brake control ..

All four RV brakes are wired in parallel.. The signal that is sent to one brake manet is the same as the other 3.. ( voltage and amp )..

I would pull that hub back off and check:
1. Measure the resistance of that brake magnet ( 3.2 ohms ) typical
2. Use a straight edge and measure across the magnet surface for overall flatness of the magnet face
3. Check the two wires leading into the coil on the magnet for any evidence of damage, looseness, etc
4. Check the operation of the self adjust mechanism on that brake ( the brakes adjust themselves Only when brakes are applied and moving forward)

When I inspected the wires during my initial troubleshooting I did not find anything loose or damaged. Did not check the resistance of the brake magnet so this is something I will check. When checking the resistance I will also check the surface with a straight edge. As for the brake adjustment I did check this and all the brakes seem to be properly adjusted. In fact this was one of the first things I checked.

Appreciate your response and some additional things to troubleshoot.