Trailer "jumps/hops/skids" When Braking Empty/Light Load

Discussion in 'Experienced Truckers' Advice' started by KWP_15, May 22, 2020.

  1. KWP_15

    KWP_15 Bobtail Member

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    .
     
    Last edited: May 23, 2020
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  3. KWP_15

    KWP_15 Bobtail Member

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    This trailer has no shocks, just airbags I recently replaced all 4. I've never seen the trailer abs light come on either. I guess I'll just have the shop replace the valve again.
     
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  5. Rideandrepair

    Rideandrepair Road Train Member

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    Make sure the height is set correctly, mine did it real bad, when air bags were over inflated
     
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  6. Rideandrepair

    Rideandrepair Road Train Member

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    Does it come on at all, it should come on when keys turned on, for a few seconds, if not, it’s not getting power, obviously. I had to replace the short power harness to ecu. ( the one that hangs with the air lines. Once I had power, and abs light was working, I could do a blink code diagnosis.
     
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  7. Dale thompson

    Dale thompson Road Train Member

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    I had to look this up,this zero maintenance damping has me kind of skeptical
     
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  8. KWP_15

    KWP_15 Bobtail Member

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    It does get power when I turn the key on, and comes on for a few seconds like the rest. It is probably something with this "zero maintenance dampening". It seems like trailers are getting more complicated, when they advertise it to be simpler..
     
  9. snowwy

    snowwy Road Train Member

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    I've had that problem.

    ALWAYS went away when truck gets new drums and shoes.

    THere's 10 brakes. They don't function too kindly when half are new drums and the other half are warped drums. The warped drums require a lot more pressure to stop then new drums which don't require much pressure.

    The trailer is locking up. While the truck is trying to stop.
     
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  10. abyliks

    abyliks Road Train Member

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    what do you have for a tractor? are both tractor and trailer drum? Have you tried Swapping Truck/trailer to duplicate it? Did you adjust the brakes and grease the scam/slacks?
     
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  11. KWP_15

    KWP_15 Bobtail Member

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    My tractor is a fairly new 2018 t680. It also has drum brakes, they are about 70%. The slacks have been greased, and all brakes have been adjusted. I guess I can try pulling the trailer with a different truck to see if it's any different.
     
  12. abyliks

    abyliks Road Train Member

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    I would try a different trailer if you could, we had one truck the truck/tractor protection valve went and would basically lock the brakes any time you hit the brake pedal, or something to atleast confirm truck side or trailer side
     
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  13. Midwest Trucker

    Midwest Trucker Road Train Member

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    I have the same problem recently. Hoping you get this figured out for both our sake! I was told it’s the control valve but sounds like you already changed that.

    For my problem it’s not the tractor brakes either. Doesn’t matter which truck pulls it.
     
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