Troubleshooting Atwood Surge Actuator Causing Brakes to Drag or Lock Up

Question:

Atwood brake surge actuator - seems to be causing brakes to drag and sometimes lockup. Purchased and installed an 84132 in Jan/2018. It seems to have worked well until recently. To overcome the problem I have had to crack open a hydraulic line connection to relieve the pressure - then it works fine for awhile. Might the master cylinder be mounted too much forward in the slots. I have two other Atwoods on trailers and note that the master cylinders are mounted more in the centre. Does Atwood have any technical or instructions on adjustments, etc? I note that only DOT 3 fluid should be used. I have used DOT 5 in my other Atwoods. I plan to check the drum and linings to see how badly they have become overheated. Any suggestions before I start doing any further diagnosis? Your help would be much appreciated.

asked by: Al W

Expert Reply:

From what you are describing, it sounds like there might be a clog somewhere in the brake lines on your trailer. This can essentially cause pressure in the lines because the fluid can only go one way, meaning there won't be adequate relief after disengaging the brakes in the tow vehicle. What I recommend doing is bleeding the brake lines, starting at the brake assemblies on the trailer. I have attached a short video demonstration that for this process that you can use for reference.

The position of the master cylinder is likely not the issue, as this isn't really something that can be adjusted on the Atwood actuator. While I do recommend adhering to Atwood's suggestion for DOT 3 fluid, I also doubt that this is the cause of your issues.

Atwood is no longer in business and there aren't any specific troubleshooting guides or instructions available. If bleeding the brake lines do not resolve the issue, please let me know and I will be happy to look into this further.

expert reply by: Chris R