Weak drum brakes - how to fix them

[toolman.dustin]

How to fix weak drum brakes (drum, not hydraulic)

If you're not satisfied with how you're electric brakes perform, have difficulty stopping your trailer you'll want to read this.
If you replace your brake shoes or brake assemblies, you should have the brakes ARCed before installing them on your trailer.

Even when I set my brake controller to 10, I have a very difficult time stopping the trailer. Weak brakes.

Background:
Originally I had 4400 lb axles on the trailer with 10" brakes. I could easily stop the trailer using a brake controller setting of 3.5.
I changed out the axles to 5600 lb and I was automatically upped to 12" brakes. I could easily stop the trailer with a setting of 2.5. Any higher than 4 and the tires would lock up and smoke.

But, I adjusted them too tightly and they rubbed while I was driving and after 1000 miles they were cooked and would grab every time I touched the brakes.
I contacted Dexter and they quickly sent me new 12" brake shoe assemblies.

Current problem:
Since replacing the brake assemblies I'm have a very difficult time stopping the trailer, even using a brake controller setting of 10.

Here's the problem. The curve of the brake shoes (called the ARC) is different than the curve of the brake drums. I know this because I checked them.

Apparently, when you buy a new axle that includes brake assemblies and drums the brake pads are ARCed at the factory to match the curve of the drum.
Since I got replacement shoe assemblies they are not ground (ARCed) to match the drums.

So, I pulled the drums off and sure enough, all 4 pairs of brakes are only making contact on about 1.5" of the ends of each 12" brake pad (8 pads). There are no wear marks at all in the middle of the brake pads.

I need to find someone who can ARC the shoes (grind them) to match the curve of the drum. In the 1960's when I was a teen, this was common practice and most any garage or parts store would do this for you for a couple of dollars. I'm going to have to try and find a place that can do this.

Here's a short video that demonstrates the problem and shows how this is done and why it's important.

https://www.youtube.com/watch?v=T0sdYjuyIYQ

Dustin

[dagst1]

Dexter and Lippert have directions on how to burnish in the new break shoes.

[toolman.dustin]

Originally Posted by dagst1

Dexter and Lippert have directions on how to burnish in the new break shoes.

dagst1 - Thanks for the post. Below is a link to the Lippert brake-in/burnish video. I've done this. In fact, I've driven 5,000 miles pretty much using only the trailer brakes (manual use of the brake controller) for stopping to try and wear them in. I've removed all the shoes and I'll find wheel/axle shop to ARC them today and see if that helps.

This video says to get them up to 350-400 degrees (F). Not sure I ever got the drum to 350. I've checked them numerous times with a laser temp gauge but I don't recall seeing over 200.

https://www.youtube.com/watch?v=d9HDloz9fq8

thanks again.
Dustin