What Info is Needed to Add Surge Brakes to a Trailer

Updated 06/02/2025 | Published 06/01/2025

Question:

I’m looking to convert my boat trailer from surge drum brakes to either surge disc or maybe even electric. It’s a 20 ft boat with dual axles. Brakes just on the rear. What information would you need to make a recommendation of the parts needed? I have pictures and wrote down the part numbers for the bearings etc.

asked by: Joe G

Expert Reply:

Hey Joe, to pick out the correct parts needed to convert your trailer to either brake style will require knowing the axle capacity as well as the wheel bolt pattern. That's basically all that's needed. Since you have the bearing numbers already that can be used to determine that as well.

In meantime I attached a couple links to this page down below that detail what you need to do to add brakes to your trailer.

expert reply by: Jameson C

Joe

6/2/2025

L68149 and L44649 are the bearings. Wheel bolt is 5 on 4.5.

Jameson C.

6/2/2025

@Joe Perfect! So you have 3,500 lb axles which means for a kit to convert to electric over hydraulic that has everything you'd need you'd want the Hydrastar Disc Brake Kit part # HYD42FR and you'd be set. Do you want a surge setup option as well?

Joe

6/2/2025

@JamesonC yes please, the surge master cylinder leaks so I would need that as well.

Jameson C.

6/2/2025

@Joe For the actuator you'd need the part # DM62VR, for the hub/rotor kit you'd want the # KOD59FR. For the brake line kit you'd then want the # 20TA-BLKIT and you'd be set.