Ive searched the forums....Unloader valve.

Discussion in 'Heavy Duty Diesel Truck Mechanics Forum' started by nikmirbre, Jan 21, 2020.

  1. nikmirbre

    nikmirbre Road Train Member

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    I believe that right before the dryer spits, this is where my air is coming from.
     
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  3. nikmirbre

    nikmirbre Road Train Member

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    Im gonna check it out in the morning. I should've posted this thread this morning LOL
     
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  4. spsauerland

    spsauerland Road Train Member

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    Looks like a BA922 compressor. Here is service data sheet.
     

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  5. mhyn

    mhyn Road Train Member

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    BA922 compressor on 12.7L Detroit ?
     
  6. spsauerland

    spsauerland Road Train Member

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    It isn't a TU-FLO 550 if you look at cooling fins. 12.7L EGR motor originally is my guess that pulled a tank to have the big CFM air compressor.
     
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  7. nikmirbre

    nikmirbre Road Train Member

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    Its been raining since I've been home and haven't had time to check properly. You're right @Hulld the unloader valves are located under the hoses. Are those as simple as unscrew old ones and insert new ones?

    So I go get in the truck this morning and air dryer is popping off every 5 seconds. And my air was down to about 75psi on the dash when I started truck up.
     
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  8. nikmirbre

    nikmirbre Road Train Member

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    @Hulld. I read that whole manual. While I can't do all those tests, I can learn to replace the small items like the governor/unloader valves/dryer, etc. Thank you for that
     
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  9. Hulld

    Hulld Road Train Member

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    If you remove the torx headed bolts from the oval plates the unloader valves are underneath and pull out from the top.
    Are you sure your air governor and air dryer are working properly?
     
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  10. nikmirbre

    nikmirbre Road Train Member

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    im gonna replace my air governor also since its cheap issue(if it is the issue) and easy to fix myself. I question the purge valve on the dryer because a few months ago it was cold and I had to get under there and kinda poke it because it was stuck one super cold morning in Tennessee. I think the air dryer itself is fine.
     
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  11. Hulld

    Hulld Road Train Member

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    Come be.
    For most air dryers you can buy a kit to rebuild the purge valve if needed.
     
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