Troubleshooting Car Hauler Brakes that Stopped Working

Updated 02/17/2016 | Published 02/15/2016

Question:

Ive asked questions before and am amazed by the fast response so thanks in advance. I have a cargo mate 28foot enclosed hauler it has the 6 lug wheels. The brakes do no work but used to and it has been sitting around 5 years. So I want to replace the whole backing and set up but I just ought this trailer and do not know about much of it. Which ones would I want to go with?

asked by: Steve T

Helpful Expert Reply:

I am glad we were able to help!!

Before you replace the assemblies let's first determine if they are the problem. I would hate to have you replace everything and then find out the problem was just a bad ground or a dirty pin on the trailer wiring connector.

First and easiest thing to check is for corrosion on the trailer connector. This is typically the problem and is an easy fix. Try hitting the pin with some sandpaper to clean it off and provide a clean contact point. Try and see if they work now.

Next find the brake output pin on the connector of the trailer. If it is a 7-way it will be the pin in the 7:00 position. Try running a jumper wire from a vehicle battery to this pin. You should hear the brake assemblies begin to hum as they activate. If not, then that indicates that either the wire has a short in it between the connector and the assemblies (you would need to look for and fix any cut or exposed wire), or the ground of the trailer isn't sufficient enough to activate the brakes.

Improving the main ground of the trailer should help at this point. There will be a wire from the connector that runs straight to the trailer frame. Make sure it is making a solid, clean connection.

Otherwise you could have some bad trailer magnets. I attached a help article on magnet troubleshooting as well.

If you still can't figure it out email me back with how the tests went and I will help you further. I suspect it's a short on the wiring or a dirty connector for what it's worth.

To pick out the correct brake assemblies for your trailer you need to know a few things.

You will want to measure the inner diameter of your hub/drums and the depth of the drums to determine what brake assembly dimensions you need. For example the part # 40716 that you referenced is a 10 inch by 2-1/4 inch thick brake assembly.

You also want to determine what the bolt pattern is of your assembly mounting flange. The standard size is 4 on 4 inch. You also want to determine the axle capacity of your trailer and go with an assembly that has the same rating, the # 40716 has a 3,500 lb capacity.