Brakes Grab and Release on Trailer While Braking

Question:

On this 2014 Cruise-Lite travel trailer the brakes grab and release many times when stopping, causing a violent jerking of both the tow vehicle and trailer. I have a Prodigy 2 brake controller and my trailer has brakes on both axles. I have tried every setting imaginable on the controller and the only way to stop this is to reduce the braking to the point where there isnt much braking happening at all. I am wondering if the problem is with the controller or with the brakes. The magnets seem a little worn but I dont know how much wear to expect before they need to be replaced. The shoes and almost like new and show little wear. Im not sure about the drum but with so little wear on the shoes, I doubt the drum is the problem. I have attached a picture of one of the assemblies showing the magnet. These 2 pictures were taken before I cleaned the grease and installed new bearings with new rear seals. So please ignore the grease all over everything. Thanks for visually evaluating the magnets for me!

asked by: Mo

Helpful Expert Reply:

The issue of your trailer brakes constantly grabbing and releasing could be caused by several different things. The first thing I would check is the boost settings on your Tekonsha Prodigy P2 Trailer Brake Controller part # 90885. I know you said you checked the settings but not everyone is aware of the boost feature on this controller. You can see these adjustments on page 5-6 in your owner's manual.

Once you have checked the boost settings you will then need to make sure the controller is putting out the correct amount of power. First sever the blue wire from the back of the controller and then test the wire while the manual override is engaged at different gain settings. There should only be 12 volts at peak settings. If you get 12 volt at the lower settings then there is an internal error in the brake controller and it will need to be replaced.

The next thing you are going to want to check is the brake output wire that runs from the brake controller all the way back to each braking assemblies. This is not an easy job but is a very important one. The wire loom needs to be removed and every part of the wire needs to be visually inspected to be sure there are no breaks or frays. Pay special attention to the where they meet at the trailer connectors. You can also replace this wire with part # 10-1-1 (per foot).

The last and final step would be to test the brake magnets. The photo you sent it does not appear to show anything that would cause too much concern but that does not mean the magnets could not still be bad. I have attached a help article for you which goes over the process you will need to perform in order to troubleshoot the brake magnets.

expert reply by: Conner L