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big_murph_279's avatar
big_murph_279
Explorer
May 10, 2014

Trailer Brakes

I have a 07 Salem 27rb that developed a brake issue a while back. When I got the trailer (new), the brakes were great. My Reese controller couldn't be set at more than 3.5-4.0. After a few years it seemed that some days it would stop great and other days it wouldn't. Lately, I have had to have it set at 6 or 7 and it still isn't as good as it use to be. I was working with the wheel bearings the other night and decided to try to diagnose the brakes while the drums were off. The rear brakes were about 1/2 worn out while the front axles brakes were almost new. I adjusted everything up and test drove it. Brakes felt the same as before. When I pulled into my neighborhood, I applied the manual brake on the control and left it on for a block or two. When I got home I checked the wheels and the rear wheels were hot. The front wheels were cold. I could touch the drums. I felt like I had a wire problem. I jacked the trailer up and with the trailer light/brake cable unhooked from the truck, I pulled the break-away cable to apply the brakes. Both rear brakes lock and one of the front brakes locked. The other didn't do anything. This is strange because when I drove it, neither wheel on the front axle was hot but yet it still locked up when the cable was pulled. I checked the ohms on the trailer brakes today. I got .8 ohms. That was checking at the trailer brake/light cable. This is the first time I've tried to diagnose a electrical brake issue. Anybody know what I should do next?
Thanks, Jeff

8 Replies

  • Fleetwood99's avatar
    Fleetwood99
    Explorer
    May 11, 2014
    Sounds like a bad negative(B-) aka ground wire.

    Is B-/grounding for front Mag's to trailer frame or to the axle? Good B- wiring thought your Plug?

    Try using a Jumper Cable from Frame to Axle for a quickee test to see if, front brakes start working maybe. 9 times out 10 its a bad ground wire. Rust is also not our friend in most gremlin hunt's.

    Good luck on your mission.
  • big_murph_279's avatar
    big_murph_279
    Explorer
    May 10, 2014
    I have adjusted every year. I just had everything apart and there is no grease on any of the parts. I just don't understand why the front axle doesn't work at all while driving. No heat at all on the front axle. When I pull the safety brake-away swith, one front wheel stops but the other doesn't. Seems like the one that is stopping when the switch is pulled would work when driving.
  • kaydeejay's avatar
    kaydeejay
    Explorer
    May 10, 2014
    donn0128 wrote:
    Have you ever adjused the brakes? It is rare for trailer brakes to be self adjusting.
    X 2. Most likely culprit for deterioration of performance.
    That or grease has got by the seals and is on the brake linings.
  • therink's avatar
    therink
    Explorer
    May 10, 2014
    When parked and applying the tow vehicle brakes, have someone listen closely and place hand on each trailer wheel hub. You should feel and hear a hum at each wheel which would confirm that each wheel is getting power to each brake. If that is ok, then you likely need to service and or adjust the brakes. Could also be one or more blown wheel bearing seals allowing grease to contaminate the brake lining.
  • danager's avatar
    danager
    Explorer
    May 10, 2014
    When you pull the break away pin, you are applying full voltage to the brakes. This is like cranking the trailer brake controller up to 11 and standing on the brake pedal.

    I would begin by getting a brake drum calliper and checking that the brakes are adjusted correctly. If they are, you would then need to check the magnets on the front axle.
  • Old-Biscuit's avatar
    Old-Biscuit
    Explorer III
    May 10, 2014
    Check the brake wiring to each wheel magnet.......need good, solid, clean connections


    Check the grounding of brake magnets

    Check the brake wiring that goes across trailer to other wheels.
    Sometimes it goes inside the axle tube and the insulation gets cut/worn off.

    Manually adjust the brakes on each wheel position.
  • donn0128's avatar
    donn0128
    Explorer II
    May 10, 2014
    Have you ever adjused the brakes? It is rare for trailer brakes to be self adjusting.

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