Weak Trailer Brakes on New Trailer Towed with 2015 Chevy Silverado with Factory Brake Controller

Question:

I just picked up a new enclosed trailer. I followed GM’s process for adjusting brake gain. I moved all the way up to max setting and while empty, still can’t get brakes to lock up. At 10 setting it slows the truck but doesn’t stop it. It’s a 8.5x20 enclosed trailer... dexter 6000 lb axles. I’m not putting a car in this thing until I get some good brakes. What should I look at first?

asked by: Josh

Helpful Expert Reply:

If the trailer is brand-spankin' new (just came off the lot) OR had new brakes installed then the issue is likely that the brakes are not adjusted out as far as they need to be. Even with self-adjusting brakes there is an initial adjustment needed to get the maximum braking power right away.

You can use adjustment spoon # W80630 to adjust the brakes. I have linked a video showing how it works. You will want to adjust the shoes outward until you can hear a slight but constant drag of the pads on the drum.

If the brakes are adjusted out properly then there could be an electrical issue. You can test for voltage on the brake output pin (5 o'clock' position) on the truck using a meter such as # PT89ZR. Have someone sit in the truck and fully activate the manual override. You should be getting 12-ish volts. If you are not and the controller is cranked up to the maximum output then there is either a problem with the controller or a wiring issue between the controller and the connector.

If you do get the maximum voltage when testing then the issue is on the trailer side. You can trace the wiring and see if there are any pinched or damaged wires and fix as needed. The magnets should be grounded to a clean metal surface. You might try moving the magnet grounds closer to the magnets as well.

expert reply by: Michael H