Johnson Bar not working

Discussion in 'Trucks [ Eighteen Wheelers ]' started by LeeStone18, May 27, 2020.

  1. LeeStone18

    LeeStone18 Bobtail Member

    3
    0
    May 27, 2020
    0
    On my trailer the brakes release and compress properly (using foot pedal brakes) but the Johnson bar does not. Ive tried it with a different trailer and the Johnson bar works correctly. Tanks hold air and air on the service side seems to be working correctly. What could the issue be?
     
  2. Truckers Report Jobs

    Trucking Jobs in 30 seconds

    Every month 400 people find a job with the help of TruckersReport.

  3. scott180

    scott180 Medium Load Member

    361
    1,084
    Dec 10, 2012
    Tooele, UT
    0
    When you set the trailer brakes do they engage?
    If so it has to be something wrong in that one component.
    Sorry but that's all I got. Good luck
     
  4. LeeStone18

    LeeStone18 Bobtail Member

    3
    0
    May 27, 2020
    0
  5. AModelCat

    AModelCat Road Train Member

    16,266
    67,452
    Jul 7, 2015
    Edmonton
    0
    Typically the service line to the trailer is supplied VIA a 2 way check valve that takes the higher of the 2 pressures (foot treadle or trailer spike) and feeds it to the trailer. I know you said it worked fine with a different trailer but I honestly think it was a pure coincidence.

    If I were to take a shot at it I'd suspect either the trailer spike itself is faulty or that 2 way check valve supplying the trailer service line is sticky.
     
    Snailexpress and 650cat425 Thank this.
  6. LeeStone18

    LeeStone18 Bobtail Member

    3
    0
    May 27, 2020
    0
    Even with a different truck hooked up. Same issue. Could it still be the service valve
     
  7. GoneButNotForgotten

    GoneButNotForgotten Medium Load Member

    615
    689
    Dec 30, 2009
    Roxboro, N.C.
    0
    Yea, the older I get, the more problems I've had with the ole Johnson Bar. It happens.
     
    mpd240 Thanks this.
  8. AModelCat

    AModelCat Road Train Member

    16,266
    67,452
    Jul 7, 2015
    Edmonton
    0
    If it does the exact same thing when you put another truck on that particular trailer, then I'd have to say that the service brakes wouldn't be working with the foot treadle either.
     
  9. WitchingHour

    WitchingHour Road Train Member

    3,401
    2,095
    Apr 1, 2011
    Broomfield, CO
    0
    Well, have you dismounted it, disconnected the outlet hose, and seen if it discharges air? I’d start there.
     
    spsauerland and lester Thank this.
  10. spsauerland

    spsauerland Road Train Member

    3,144
    8,054
    May 31, 2010
    West Harrison, In
    0
    Or just disconnect blue gladhand, and check for air flow when using footvalve and trailer hand brake valve.
     
    Roberts450, lester and 650cat425 Thank this.
  • Truckers Report Jobs

    Trucking Jobs in 30 seconds

    Every month 400 people find a job with the help of TruckersReport.

  • Draft saved Draft deleted