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JosephA's avatar
JosephA
Explorer
Jul 28, 2014

How I bettered my 5'ers brakes

Like many I felt that the electric brakes on my fiver were weak and like many, set out to the internet to find an answer. Most answers were to check the condition of the shoes, magnets, etc. but the one that stood out was to check the amperage draw of the magnets. More internet searching showed that for the 12X2 brakes on the Dexter 7,000lb axles, each magnet should draw a max of 3amps @ 13.8VDC. After checking each magnet individually I found that each drew a healthy 3amps.

Thinking there was more to this I thought about how I checked each magnet. Power was applied to the individual magnet while all others were disconnected. Well what about if 2 or more magnets were tested at one time? Going for broke I measured the draw at the 7-way truck connector by manually applying full power from the brake controller and came up with 9.5amps total which was about only 80% of the expected 12amps.

After digging into the wiring a bit more I saw that the wires used from the 7-way connector back to the axles was 14awg. Was glad to see they did use a dedicated + and - for the brakes but 14awg to carry 160+ watts for a distance over 40ft? To cut to the chase I went to Lowe's and bought 45ft of 8awg stranded primary wire. I used the new primary wire for the - feed and used both of the original wires (14awg wire is about 1/2 the thickness of 8awg) for the +. Along the way I removed the crimps and soldered every connection. Now when I measure the draw at the 7-way connector I get a reading of 11.5amps and while still not perfect, there is a huge improvement in the trailer brakes. This combined with the Hawk SD brake shoes on the TV make for an absolutely incredible difference in stopping power.

Hope this helps someone.

Joseph
  • Sounds like a cheaper fix than buying disk brakes. :) Thanks for the write-up.

    I'm going to check my triple axle and see how much draw I have. I have the 7,000 lb. Dexter axles and 12 inch brakes. This could be interesting.
  • Thanks for the post...wish I had seen it back in 2007. I was never happy with the braking on my 5th wheel. I had checked the output at the plug and was getting 12 amps so I chalked it up to the heavy weight of the 5'er.

    I ended up buying a new truck that came with a digital controller installed. What a difference. The 5th wheel brakes operated exactly how I had expected them to. I had plenty of braking power.

    I remember the power wire for the controller on the old truck was 14AWG plus it was connected to some sort of boost device (I bypassed it). Based on your post, I'm guessing an 8awg wire may have solved the poor brake performance.
  • I haven't given this much thought before but, I am also wondering what gauge wire the truck manufacturer used from the brake controller connector under the instrument panel to the 7 way connector at the rear. Also, the wires that are part of the controller are 14 ga.

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