Troubleshooting Dexter 10 inch Brakes not Holding the Truck and Trailer and Magnets Touching Drum

Question:

I installed dexter 10in brakes and drums on 1axle of axle home made tlr. I notice the magnets litely rub the drums even when it is not pluged in to truck the springs behind the magnets are causing this. Ihave a 2011 ford with factery brake controler and even when set to max I get very feeble at best brake app. it willnot even hold from rolling in gear at idle the brakes seemto work behind a differant truck with Prodegy controler. I am concernd about th magnets rubbing the drums and I plan to take the truck to ford to have it checked. Do you have any other info. I can relay to ford

asked by: Robert T

Expert Reply:

It sounds as if you may have to adjust the trailer brakes or have a wiring issue. When the 10 inch brakes, part # AKEBRK-35L and # AKEBRK-35R, are installed on the trailer the brake magnet should release as long as there is no power to the magnets. The spring should not interfere with the release of the magnet as long as the brake assembly is assembled correctly, you should verify that the brake assemblies are assembled correctly. There is no adjustment of the brake arm that holds the magnet and some initial break in may be required. If they are correct, you may be hearing the brake linings rubbing on the drum and not the magnet.

I would start off with adjusting the trailer brakes properly. We have a video, see link, that explains this in detail. At the 4 minute 23 second mark adjusting the brakes is shown.

Next, check the power wire going to the brake assembly with a multimeter, # PT89ZR if needed, and make sure that there is no power on this circuit when the trailer is connected to the truck and the brakes and brake controller are not activated. If there is residual power on the output wire, check the truck and trailer connectors to be sure there is no corrosion or wiring issues causing a bleed over of power on the circuit. If there is a breakaway kit installed on the trailer the breakaway battery could be the cause of residual power, the breakaway kit wiring should be checked for proper installation.

If there is power on the brake output wire when idle and no explanation for it, the brake controller in the cab most likely has an internal issue.

Trailer brakes are not designed to hold the trailer and the vehicle, even at idle. The Dexter 10 inch brake assemblies are designed for trailers and their associated loads up to 3,500 lbs and will not be able to hold the truck without the trucks brakes applied in most situations. To properly test your trailer brakes you should warm the brakes by applying the manual slide at a slow speed several times. Then you can use the manual knob to apply the brakes fully. If the trailer brakes lock up you will need to back the power level down, if the trailer braking is not sufficient you will turn the power up. You want the trailer brakes to be adjusted to a point just below lockup for the best performance.

If you find that the controller in the truck is working correctly and the trailer is still not braking sufficiently, you may need to upgrade the trailer brake wiring on the trailer to a larger gauge wire. We recommend using 10 gauge wire. The double bonded 10 gauge wire, # 10-2-1, is the wire I would go with.