Parts Needed To Add Electric Drum Brakes To A Flatbed Utility Trailer

Updated 03/11/2024 | Published 03/10/2024

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Question:

Hello, have a question regarding adding electric brakes to a 16ft flatbed utility trailer. It has twin 3500lb axles with 5 stud hub on 4 1/2 center. The vehicle which pulls it does have a factory Ford F150 electric brake controller onboard. What parts exactly would be needed to add electric brakes to rear axle? Thank you in advance for any info.

asked by: David C

Expert Reply:

Hi David,

To add brakes you'll first need to check the axles to see if there is a brake mounting flange. If not then you'll have to replace the axles in order to get one with a flange so that you can mount brake assemblies. If you do have them then you can use the etrailer Electric Trailer Brakes # AKEBRK-35-SA. These brake assemblies are self-adjusting so once you complete the initial brake bedding process you won't have to adjust the brakes again.

From there you'll need a hub/drum assembly for each brake assembly. The # AKHD-545-35-EZ-K will most likely be a fit but you'll want to doublecheck the bearing and grease seal combination you currently have in order to confirm they match. If you look at the face of the bearings and seals there should be a part number, if not then you can measure your spindle at points B, C, and D with a pair of calipers # PTW80157.

Next you'll need a 7-way cable # H20046, junction box # 3375601101, and breakaway battery # 3802346. All of the electrical wiring will run to this junction box and connect to your tow vehicle with the 7-way cable. The junction box has various posts to separate each function and keep things nice and organized. You'll have to run some 10 gauge wire # 10-1-1 from the brake controller output post in the junction box out to the brake assemblies for power. The assemblies will have two wires, one for power and the other to be grounded to the frame with a ring terminal. They aren't specific so you can use either.

Since you already have an OEM brake controller you shouldn't have to do anything to the tow vehicle after the trailer is up and running. I do recommend installing brakes on both axles though for better stopping power and because some states and even smaller municipalities will fine you for not having brake assemblies on both axles if you're over 3,000lbs.