Troubleshooting Hydraulic Drum Brakes that are Running Too Hot

Question:

I have a tandem axel boat trailer with 3,500# axels. The rear hubs have surge activated drum brakes. This winter I repacked the bearings in all four hubs and changed out the brakes the entire assembly on both sides. On my first trip, the right rear hub got extremely hot the left rear was still able to be touched. I took it into a trailer shop who said that both brakes needed adjusted. I took it for a test drive and the rear hubs were showing 225 degrees. I took it back to the repair shop and they adjusted the brakes one more time. I took the trailer for a 20 mile ride and through town. The rear brakes are now showing 160 degrees. This is acceptable or is more going on.

asked by: James D

Expert Reply:

It definitely sounds like there was just an adjustment issue with the brake assemblies on your trailer. This is pretty typical, especially right after installing new brakes. We can likely also rule out bad bearings as the cause since they were recently inspected and repacked as well. The 160 degree temperature you are getting now is much closer to normal, although they might benefit from running a bit cooler.

There is not really a "normal" temperature that brakes should be at after use, but generally speaking they shouldn't be too hot to touch. I recommend checking the assemblies once more to ensure they are adjusted properly. You can use an adjustment tool like # W80630 to rotate the star wheels on the other sides of the holes on the assembly to make the brakes more or less aggressive. I have also included a helpful demonstration video. At around the 4:35 mark you can see how to properly adjust trailer brakes.

expert reply by: Chris R