Tandem slider maintenance

Discussion in 'Experienced Truckers' Advice' started by Still undecided, Jun 25, 2022.

  1. Still undecided

    Still undecided Light Load Member

    187
    199
    Aug 21, 2019
    0
    The company I work for now has a mandatory trailer inspection before leaving the terminal yet every third trailer I get has problems with sliding the tandems. Sometimes the pins won't release, sometimes they won't come back out, sometimes the brakes won't hold to slide the tandems. WTF are they missing during these inspections? Are the tandem brakes not working as well as they should? Is there a better reason than they'd rather have the unpaid drivers deal with this crap than a paid mechanic for these problems?
     
  2. Truckers Report Jobs

    Trucking Jobs in 30 seconds

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

  3. Dave_in_AZ

    Dave_in_AZ Road Train Member

    37,529
    197,378
    May 4, 2015
    0
    If the brakes won't hold to slide the tandems, they are badly out of adjustment.

    They will sell the adjustment set to anyone. Or if your in California, just steal one.

    Let the air build up fully in the trailer(s) before you dump it to release the pins.

    Rock the trailer back and forth to get them to release, and engage.
     
  4. Big Road Skateboard

    Big Road Skateboard Road Train Member

    1,866
    7,931
    May 2, 2021
    0
    Often the pins wont release because the rails are holding pressure against them. Set your trailer brakes and rock the tandems.



    Usually not lined up with slider rail, or pulled in too far allowing them to drop behind slider rail. Use a flat tip screwdriver to lift up

    Often it's just weak brake chamber springs. Try applying more pressure by releasing your trailer brakes, and applying your hand valve (if equipped).

    And to end, most problems are caused by friction. Slilder plates are never maintained. A spray lube applied to the slider plate usually solves problems.

    1 more. If you're talking a chassis from Trac or DCLI, those are the most neglected pieces of equipment on this planet.
     
    Last edited: Jun 25, 2022
  5. Brettj3876

    Brettj3876 Road Train Member

    10,176
    47,393
    Nov 18, 2014
    Stuck in Limbo
    0
    It's a dumb question but are you letting the trailer air up fully first?
     
  6. Six9GS

    Six9GS Road Train Member

    1,425
    3,532
    Dec 3, 2012
    Yuma, AZ
    0
    You don't mention if the trailer tandems are mechanical or pneumatic. Different systems with different tricks. I use trailers with pneumatic release systems most of the time. As mentioned, you need to leave the air on (trailer brake button pushed in) for awhile to ensure the air tank has enough pressure to operate the pneumatic pins properly, before you pull the trailer brake and push the tandem pin button. I usually push the trailer brake in and leave it in until I can't hear anymore air flow. It can take a few minutes. I also have a small mallet with me. If one doesn't retract, I'll tap it with the mallet and pop it in.
    I don't have as much experience with the mechanical ones. But, I know for those, all the pins are kinda coupled together and don't work independently like the pneumatic pins. For those, rocking the trailer back and forth usually works. And, sometimes you need a pair of vice grips to hold the tandem slider bar out, as the notch that's supposed to hold it doesn't always work and hold it out like it's supposed to.
     
  7. Still undecided

    Still undecided Light Load Member

    187
    199
    Aug 21, 2019
    0
    Thanks for the replies. These are dry van trailers with both mechanical and pneumatic mechanisms. I've been using WD-40 for lubrication, lots of rocking back and forth, using the trolley brake and hitting the pins with a hammer with mixed results and will try waiting longer to allow the air pressure to build up.

    If the problem is due to the brakes being out of adjustment or weak brake chamber springs does that mean the brakes are less effective when driving? That sounds like a safety issue if it is.
     
    Last edited: Jun 26, 2022
  8. Big Road Skateboard

    Big Road Skateboard Road Train Member

    1,866
    7,931
    May 2, 2021
    0
    No. They just don't hold as well set.
     
  9. Still undecided

    Still undecided Light Load Member

    187
    199
    Aug 21, 2019
    0
    You're the first person to mention this and it does make a lot of sense. I'd never even thought about it too, I just figured all of their trailers needed more maintenance. Thanks again.
     
  10. Wasted Thyme

    Wasted Thyme Road Train Member

    7,670
    37,892
    Jan 27, 2020
    GOAT watching
    0
    The system is air operated. So if you don't allow enough air to build up. They don't function properly and only partly disengage.

    Think of how bad your brakes would be with no air.
     
  11. stuckinthemud

    stuckinthemud Medium Load Member

    559
    2,505
    Oct 20, 2013
    0
    Re trailers needing maintenance , I think you are very much correct about the trailers needing maintenance. Brakes could very easily be out adjustment. Check brake adjustment.
     
  • Truckers Report Jobs

    Trucking Jobs in 30 seconds

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

  • Draft saved Draft deleted