How to Change a Trailer Equipped with Hydraulic Surge Brakes to an Electric Brake System

A common question that we get in our Parts and Service Department at Felling Trailers is in regards to changing the brake system from Hydraulic Surge brakes to an Electric Brake System. Felling’s Parts Specialist identifies for you the step-by-step process for changing from hydraulic brakes to electric brakes.

Felling Trailers Brake Systems:

Changing from Hydraulic Brakes to an Electric Brake System

Remove All Hardware

hydraulic brake system to electric brake system

The trailer should be securely lifted and supported when maintenance or repairs are being made to the trailer. Use properly rated jack stands to support the trailer.

  • Remove all hubs/drums
  • Remove brake backers
  • Remove all brakes lines
  • Remove hydraulic harness

Install new Electric Brakes

  • Install new brake backers
  • Install brake away
  • Install electric harness
  • Install new wheel seals
  • Install the original hubs/drums
  • Weld hydraulic actuator solid

If you need additional guidance on this process or would like us to walk you through any of these steps for changing out your trailer’s brake system, please contact our Parts Specialists at [email protected] or call 1-888-335-5464.


  1. I have heard a lot of good things about electric brake systems. So, as result, I am not surprised to hear that a lot of people want them installed. I appreciate the tips for replacing them myself, but I don’t know if I trust myself to do all that!

  2. I use my boat and trailer in salt water will that affect the electric brakes and it’s still better then hydraulic one other question is do they come in disc and drum or just drum

    • Good Morning Steve,
      Saltwater can be very destructive to brakes if left to sit on the brakes. Our suggestion would be electric over hydraulic disc brakes, disc brakes are open so when you spray the trailer off the salt has less area to sit and corrode the brake components. The brakes are more expensive than regular drum brakes however the braking is much better on a disc brake and less maintenance cost.

      Hope this helps,
      Felling Trailers

  3. I have converted my surge brakes to electric brakes. The wheels get hung up without the power connected to them. Do I need to replace the drums for this conversion to work?

    • Good Morning Len,
      You shouldn’t need to replace the drums unless they are warped which created high and low spots. A local machine shop could check them and if needed turn them.

      Hope this helps,
      Felling Trailers

  4. I have a boat trailer with tandem axels,the boat is approximately 4800lb,the trailer currently has bump brake system.Can it be converted to electric disc?

    • Good afternoon Greg,
      If the axle has the correct flange already installed on the axle then to could add the disc brake caliper, in most cases, you would need to order an axle with the disc brakes already mounted.

      Hope this helps,
      Felling Trailers

  5. Frank Grimaldi says

    Hi I have just bought a Teardrop camper and want to add electric brakes for peace of mind, I have a REDARC controller already fitted from the dealer on my vehicle, apart from the actual hub etc what else do I need to wire up the hubs, please
    Kind Regards
    Frank Grimaldi

    • Felling Trailers says

      Hello Frank,

      For starters, does your trailer currently have hydraulic surge brakes or none at all?
      If it does have hydraulic surge brake you will need to decide what to do with the hydraulic actuator on the tongue. We have welded them up solid in the past when we have done conversions here. Just so it doesn’t actuate back and forth. Another option would be to remove it and have a fab shop install a better hitch plate or channel on the tongue for a coupler.

      You will then need to add a breakaway battery and switch. The only thing you will need to replace is just the brake assemblies themselves. Take off the hyd. brakes, take out the hyd. lines and install electric brake assemblies. You would have to run a wire from the brakes into the harness. We have always found it easier to replace the whole harness on the trailer to accommodate electric brakes. You should be able to get a harness from the manufacturer. This would require a 7RV plug as well to plug into the tow vehicle. You shouldn’t have to mess with the hubs themselves.

      This is how we have done it on trailers. I assume a camper shouldn’t be much different, but I highly suggest reaching out to the dealer or manufacturer just in case there is something I am not aware of.

      Felling Trailers

  6. Hi I bought my boat and trailer five years ago the brake system never worked but only had to travel a few miles to put the boat in the water and take the boat out of the water twice a year but I’ve been wanting to travel with the boat elsewhere but I don’t wanna go out of town without the brakes working it has a surge brake system I looked into having a trailer place to fix it they want a lot of money and I don’t wanna spend that kind of money is it not that hard for me that is easy enough can figure out to fix the surge brake system now the hydraulic lines I don’t know how good they are but as far as the brakes I don’t know and the box upfront I’m sure needs to be replaced next question would I be better off just putting electrical brakes system

    • Felling Trailers says

      Hi Tom,

      Sometimes it is cheaper to switch to electric brakes, assuming your truck is equipped with a brake controller.

      Not knowing the specifics of the trailer, I’m guessing a bit on the cost;

      Per axle, $260.00 for the electric brakes
      Breakaway control $50.00
      Misc. wiring and front plug $35.00


      Per axle, $249.00 for the hyd. brakes
      Brake actuator $350.00 to $500.00 depending on which actuator is needed
      Brake line kit $125.00.

      Hope this helps you with your questions.

      Felling Trailers

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