Parts Needed to Add Electric Brakes to Trailer with 3,500 Pound Axles  

Question:

Expert Reply:

To answer your last question first the trailer has been towed with no brakes so even if you only add brakes to one axle it will be an improvement.

Based on your measurements I'm thinking your inner bearings are # L68149 (1.378 inch diameter) and outer bearings are # L44649 (1.063 inch diameter). Very close to what you have but you'll want to double check like you mentioned.

If these bearings are correct the hub and drum assembly for your trailer is # AKHD-545-35-K. If they're not the correct bearings let me know what numbers you have and I'll find what hub you need.

With a 3,500 pound axle you'll need brake flanges with a 4-bolt pattern like # 4-35. Your trailer may already have these and if so that's good. The brake flange needs to be welded to the end of the axle to support the brake assemblies. It will need to be welded perfectly straight for your brakes to function properly so the work should be performed by a certified trailer shop.

You're going to need to wire the trailer to power the brakes. This will require a 7-way trailer connector, like # HS381-9000. Then use 10 gauge wire # 10-1-1, which is sold by the foot, to run the wire from the 7-way to the trailer's brakes.

The trailer will require a breakaway kit. The Hopkins Engager # 20099 is our most popular kit. The breakaway kit engages the trailer's brakes in the event the trailer is separated from your tow vehicle.

In order to control the trailer's brakes you must have an electric brake controller in your tow vehicle. If you don't already have one I suggest the Prodigy P2 # 90885 because of how reliable and easy to use it is. Its one of our top brake controllers. Your 2002 GMC Sierra 1500 has a connector under the dashboard to plug in the controller using # 3025-P.

And finally you'll need brakes. I suggest the # AKEBRK-35-SA brake kit that includes both brake assemblies. These are self-adjusting so they'll need to be manually adjusted once when they're installed and never again.

I've linked some videos on the products I've recommended for you to take a look at.

expert reply by: Charles S

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Randy S.

3/1/2017

Thank you for your continued patience and expert advice, but wanted to confirm a couple of things before finalizing the order. From previous communication: 2002 GMC Sierra 1/2 ton pickup 1991 Big Tex 16 ft utility trailer AKEBRK-35-SA Brake kit 1 AKHD-550-35-K 5 ON 5 Wheel pattern L68149/L44649 bearings/races 2 H20043 Wire connector 1 90885 Prodigy P2 Controller 1 3025-P Wiring adaptor 1 20099 BreakAway Kit 1 10-1-1 Wire ? Questions: How much wire is generally needed for 16 foot trailer? Do you sell the 7-way plug for the vehicle for the trailer connection? Is there anything else you might recommend? Again, thank you for your patience and help

Charles S.

3/13/2017

It definitely sounds like you've got your list made out. Orignally I recommended the # AKHD-545-35-K hub and drum assembly with a 5 on 4-1/2 bolt pattern but if you have a 5 on 5 then you'll want # AKHD-550-35-K like you said. For the 7-way trailer connector on the back of your 2002 GMC Sierra you can use # 74682. This will provide the 7-way as well as a 4-way in case you ever need it. You'll definitely want to have more than enough of the # 10-1-1 because it's better to have extra than run out and have to get more. For a 16 foot trailer and using the # H20043 you'll probably need about 25 feet. However, another option that might be better is to use # 277-000141 which is a different connector that attaches to a junction box. The lead is also 10 feet long. So I suggest about 20 feet of # 10-1-1 with this route. With the junction box you'll also need ring terminals # 44-5310A.