Converting From Hydraulic to Electric Brakes on Boat Trailer  

Question:

Expert Reply:

Hi Jeffrey; to find your bearings you will need to either identify the axle with the serial number on the axle tag or pull the hubs. If you pull the hubs you may be able to find part numbers stamped in the side. If they're missing or worn you need to measure the inner diameter using a digital caliper # PTW80157. If you can add this information to the comments below I can help you find hubs/electric brakes.

You will also need to add 7-way wiring like the # H20046 and a breakaway kit like # 20400. If you only have a 4-way/5-way on the vehicle side you will need to upgrade to a 7-way as well using the # ETBC7. It is possible there is a custom 7-way wiring harness for your vehicle but I would need to know the year, make, and model to check.

For a brake controller, I recommend the Redarc Tow-Pro Liberty # RED24FR. The Liberty is incredibly reliable and doesn't take up space in your vehicle. The main unit mounts behind the dash so the control knob will be the only thing visible in the cab. This may also have a custom wiring harness for installation, otherwise you need the # RED69FR which is the universal wiring harness.

expert reply by: Robin H

0

Bearing Identification
(click to enlarge)

Robin H.

2/3/2026

Hey Jeffrey, were you able to find the bearing numbers or measure the inner diameters for your boat trailer hubs? Once you have that info, I can help you match the right hubs and electric brakes. Let me know what you find so we can narrow it down.