389 cab air bag

Discussion in 'Peterbilt Forum' started by Agtrucker, Apr 8, 2020.

  1. Agtrucker

    Agtrucker Light Load Member

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    Dealing with a ‘19 389 daycab. When you grab the side cab bar the cab doesn’t move at it. I’ve been asking our shop to soften the cab air bags just a bit since the start of the new year. They seem uninterested so I’ll just do it myself but I’d like to know what is considered spec for the cab air bag measurement. Also all I need to do is just pull the threaded rod off and shorten it a bit right? Thanks
     
  2. AModelCat

    AModelCat Road Train Member

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    You can't "soften" airbags. Take air out, cab height drops. Cab height drops, there's a risk it can bottom out and damage stuff. The shop isn't uninterested, they just don't want to see equipment get needlessly damaged.
     
  3. Agtrucker

    Agtrucker Light Load Member

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    Well I think you got what I meant, Geez...I’m not looking to drop the height by inches, just so there’s some flex when I enter the cab. All the other trucks I’ve driven have so.... I barely weigh 150lbs so that mated with rock hard cab bags and air trac rear makes a pretty harsh ride
     
  4. PE_T

    PE_T Road Train Member

    You can probably find some videos of cab air bag replacement for a 389, but as already mentioned, air bags cannot be soften. Perhaps you have a different problem like worn cab mounts, particularly on older trucks. The bushings can go bad and make the ride not feel smooth. Another more common problem is bad shocks.
     
  5. Rubber duck kw

    Rubber duck kw Road Train Member

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    I would talk to the local Pete dealer, sounds like the ride height for the cab is too high.
     
  6. Chubby Fly

    Chubby Fly Medium Load Member

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    his ride heigh on the cab is fine. Sounds like he is used to one of those sloppy cascadia cabs. the ones that rock back and forth when you climb in the truck. 379 and 389 dont move around like that. If you think that truck is a harsh ride, theres alot of people on here that would gladly trade with you.
     
  7. Rubber duck kw

    Rubber duck kw Road Train Member

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    Guess I was assuming the other trucks he was talking about having driven were also 389s at the same job. The only Pete I have any real knowledge about is an old 359, which doesn't have air ride on the cab or sleeper. Like I said, talk to the dealer and see where it's supposed to be at is the only way to know if there's any softening the ride.
     
    Agtrucker and Chubby Fly Thank this.
  8. Agtrucker

    Agtrucker Light Load Member

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    Dec 14, 2011
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    Ok, carry on.... guess it just seemed logical that with the use of threaded rod on the linkage, it was there to allow for some adjustment. Otherwise why not just use a fixed rod and call it good.
     
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