Trailer pulling to the left when trailer brakes applied

[Wayne]

When I apply the trailer brakes either manually or through the automatic controller, I can feel the front of the trailer pulling to the left. This means the trailer brakes on the left are applying more than the trailer brakes on the right. I inspected the brakes this winter and see zero difference in condition of the brake shoes, drums, or adjustment. Any idea what could be causing the left brakes to apply more than the right brakes?

 

[spasm3]

Usually the rule of thumb with brakes are;

When a pull to one side is happening with no brakes applied, the issue is on the side of the pull.

When a pull to one side occurs when braking, the issue is on the opposite site of the pull.

I'd check the right side shoes for grease contamination.

 

[Wayne]

Ah, so it's probably not because the left side brakes are doing more work, it's because the right side brakes are doing less. Never thought of it that way - thanks. When I pulled the hubs, all four brakes and drums looked identical with almost no wear. I'm a bit puzzled, unless the auto adjusters aren't working yet because there is so little wear? I'm just grasping at straws.

 

[dnewton3]

The typical causes of bad braking are these:
- improper adjustment of the shoes (traditional elec brakes)
- poor electrical connections
- altered coefficient of friction (grease/oil where it doesn't belong; on the brake surface)
- badly over/under inflated tires (not a little, but a lot)
- electric over hydraulic are similar except for the nuances unique to the pressure circuit

My RV does not have auto adjusters, and I'm OK with that. I've heard they are not that reliable, and perhaps that's what you're into? I'm sure there's a way to manually adjust them- try that.

It often takes a while to get them adjusted equally. Part of that is because we want to see them adjusted as a visual reference, but we cannot "see" a weak circuit or magnet.

Because we live on a long gravel drive, I have someone drive the RV about 30mph and "lock" the trailer brakes with the controller. Then I watch to see if they all four lock-up at the same time. If not, there's typically one which is lagging; that's the one you want to tighten up a bit. My method isn't fancy, but after a few tries, it works well and is reliable.