2006 frightliner when I build max pressure it doesnt release all at once

Discussion in 'Heavy Duty Diesel Truck Mechanics Forum' started by Adamprov3nch3r, Jan 20, 2021.

  1. Adamprov3nch3r

    Adamprov3nch3r Bobtail Member

    26
    5
    Dec 26, 2020
    0
    does this help at all?
     
  2. Truckers Report Jobs

    Trucking Jobs in 30 seconds

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

  3. Rideandrepair

    Rideandrepair Road Train Member

    9,305
    22,557
    Aug 8, 2015
    0
    Maybe the safety valve mounted on the compressor head, is what you’re hearing, not the air dryer spitting. Maybe the Govenor needs adjustment, or the safety valve is weak. New air dryers sometimes spit for a long time, then break in and spit quickly. I’m confused why it spits every 2 minutes at idle, then won’t while going down the road. Never had that problem. Always a bad Govenor, spitter on dryer or bad safety valve on compressor. You say cut out/ cut in pressure is normal at idle. Yet it spits every 2 minutes. Any air leaks maybe? Sounds like maybe the Govenor is set too high, or the Safety valve is weak, and leaking a bit. When going down the road at higher RPMs you don’t hear the safety valve leaking, and compressor is pumping air faster than the valves leaking. Dryer and Govenor both being fairly new. I would make sure the rapid spitting at idle is coming from the air dryer, to rule out the safety valve. Post the cut out/ cut in readings from the gauge. Hopefully someone can help you figure it out.
     
    BoxCarKidd Thanks this.
  4. Adamprov3nch3r

    Adamprov3nch3r Bobtail Member

    26
    5
    Dec 26, 2020
    0
    Sorry i must have wrote that first message super wrong or something..... So ok before anything went wrong or I had anything replaced it worked right and purged at 120 cant remember why they were replaced right now but it wasnt even that long ago.... After replacing dryer and govoner it would get up to 140 psi and purge correctly with a real quick phhf sound weather or not the compressor would cut out at 140 and cut in at 90 to be honest i never really payd much attention to that because at the time i had some bad air leaks. Well after about 6 months after replacing the dryer and govoner during that 6 months it always going up to 140 psi and not sure when it would cut back in or just stay on. Well about a week or 2 ago the dryer stopped puring with one solid phhf it would go phhhhhhhhhhhhhhhhhhhhhhhhhhhhhffffffffff for about 30 seconds or so once it hit 140 tell it got down to about 120 or so and then it would stop. Well when im driving the compressor never stops pumping air just like at idle but its putting more air in the tanks then the dryer can let out because the dryer only goes phhhhhhhhhhhhhhhhhhhfffffffffffffff and my compressor at highway speeds creates more air then it lets off so it climbs and climbs and dont stop ive had to hold my air seat on and pump breaks every so often to keep it around 140
     
  5. Adamprov3nch3r

    Adamprov3nch3r Bobtail Member

    26
    5
    Dec 26, 2020
    0
    I hope that better explains whats happening.... At a idle the phhhhhhhhhhhhhhhhhfffffff is for the most part sufficient enough to keep me at or below 140 but compressor isnt shutting off still tho
     
  6. Adamprov3nch3r

    Adamprov3nch3r Bobtail Member

    26
    5
    Dec 26, 2020
    0
    Also ive put my hand around the compressor safety valve which by the way almost looks like it might have a hard time opening and nothing comes out of it
     
  7. Rideandrepair

    Rideandrepair Road Train Member

    9,305
    22,557
    Aug 8, 2015
    0
    Well, first thing I’d do is adjust the Govenor to cut in and out at 100/120, or 105/125. I’m only guessing the purge spring is getting weak, from purging at a higher compression. That’s only a guess. I don’t know much about it all. Just always change Govenor, air dryer, clean system with conditioner and drain tanks a few times. Last time I did mine, after freezing up, it acts funny for a day or 2. All I can suggest, is adjust Govenor, pour some air brake conditioner into the line off compressor. Run it, Drain tanks at least a couple times times, till they’re clear. Maybe clean the spitter on dryer with brake clean or ether. Might be some trash in the spitter valve. I believe the dryer and Govenor on your Truck are expensive. Depending on results. You may need to replace or rebuild the spitter. May need a new Govenor. I would try to adjust it first. Clean system, see what happens. I don’t know much more to do. If that don’t fix it, someone else may know more.
     
  • Truckers Report Jobs

    Trucking Jobs in 30 seconds

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

  • Draft saved Draft deleted