Recommended Replacement for Atwood Surge Brake Actuator 85778
Question:
Hi! The brake lockout knob on my coupler broke off. We never really cared for that coupler so as a complete novice I ordered a different brand figuring I could just swap them. Once I got to the guts I realized I was sadly mistaken. Here are my questions... 1. Can I tow the trailer safely with the broken knob? 2. Where do I find a 85778? 3. Can I use a different coupler? 4. How difficult is it to replace one of these things? Thank you very much for your help! Picture is of the former location of the lockout knob
asked by: Scott C
Expert Reply:
The manual lockout on your Atwood 85778 surge brake coupler is there so that you can back up the trailer without the brakes locking up on you. Yes you can safely tow your trailer with the broken manual lockout, you just have to make sure you don't put yourself in the situation where you have to back your trailer up.
Since Atwood went out of business there aren't any exact replacements for your coupler but you can use a different brand. The only thing I was able to find online about the 85778 is that it has a 2" coupler, is rated for 6,000 lbs and that it was used for either drum or disc brake applications. I recommend checking out the Demco Hydraulic Actuator # DM72VR for Drum or # DM62VR for Disc brakes. These are rated for 7K and are compatible with a 2" hitch ball. The drum brake option doesn't have a lockout while the disc brake application has an electric lockout. These fit a 3" wide trailer tongue and have bolt holes that are 3" apart on center.
The installation itself is pretty straightforward and I have attached a video of the drum brake actuator being installed that you can reference.

Products Referenced in This Question
Demco Hydraulic Brake Actuator w/ Electric Lockout - Disc - Zinc - 2" Ball - 7,000 lbs
- Brake Actuator
- Surge Brake Actuator
- Agricultural
- Construction
- Marine
- Travel Trailer
- Utility Trailer
- Bolt-On
- 7000 lbs GTW
- 2 Inch Ball Coupler
- Disc Brakes
- Electric Lockout
- Demco
more information >
Product Page this Question was Asked From
Demco Hydraulic Brake Actuator - Drum - Zinc - 2" Ball - 7,000 lbs
- Brake Actuator
- Surge Brake Actuator
- Agricultural
- Construction
- Marine
- Travel Trailer
- Utility Trailer
- Bolt-On
- 7000 lbs GTW
- 2 Inch Ball Coupler
- Drum Brakes
- No Lockout
- Demco
more information >
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Frank P.
10/8/2024
How do I bleed this Atwood 85778