Does Actuator of Trailer Coupler Need to be Replaced Going from Drum to Disc Brakes

Updated 12/08/2025 | Published 11/06/2025

Question:

I have a tandem boat trailer where i am replacing completely shot drum brakes with disc brakes. Do i need to change the surge accuator/tounge mechanism as well?

asked by: Mike C

Expert Reply:

Hey Mike, yes the actuator of your trailer would need to change to go from drum brakes to disc brakes because disc brakes require a lot higher pressure than drum brakes. BUT you might have an actuator that can have the master cylinder replaced with one that is for disc brakes so that would be a little easier.

Either way the Demco part # DM62VR would work as a complete replacement to work with your disc brakes. Do you have the disc brake components picked out already?

expert reply by: Jameson C

Jameson C.

12/1/2025

Hey Mike, how did the switch to disc brakes go on your tandem boat trailer? Did the new actuator setup work smoothly with your disc brake components? Your update could make it easier for the next person doing the same upgrade.

Mike C.

12/5/2025

@JamesonC The ONLY issue I had was trying to get the bearing buddies installed. I needed a bigger hammer than expected. The SeaDo trailer had the original calipers mounted at the top of the axle - not on the leading side as seen in alot of how-tos. I mountex the new ones in the same was (assuming SeaDo knew what they were doing). My only issue then was the brake lines coming 1/2 an inch away from the springs, so i rotated the inlet bloke sligjtly - which was NOTHING to do with your product. All in all, installing both sets took less time and effort than installing one on any car ive worked on in tje last 45 years.

Jameson C.

12/8/2025

@MikeC Glad you got it all installed and it wasn't too bad! I am sure you know this but don't go too crazy putting too much grease in the hubs with the Bearing Buddy as it can blow out the seals.