Heavy Equipment Forums Heavy Equipment Community

Air brake help

Orchard Ex ยท 2011-02-14 16:41

When my compressor kicks in, this valve: that is under the air dryer: isn't setting like it's supposed too. At idle it will just leak out everything that the compressor is sending. If I give it a little shove it sets and works fine for that cycle then does the same thing when the compressor kicks on next time. It works fine if the truck is running at speed. Before I go tearing into something and screw it up, what does it likely need? A new valve, need to be cleaned, more fiber in the diet? Thanks

Replies7
  1. #1Water Doc2011-02-14 19:05

    Ahh the ole Bendix ADIP. That valve at the bottom of the dryer is the purge valve. When these dryers first came out we had all sorts of issues with them spitting when building air. There was an updated purge valvre and special o ring lubricant kit that we used to put in them. I don't recall the part numbers but any Paccar dealer should know about it. Came in a bag, a couple of orings depending on which dryer you have, a new white purge valve, a tube of lube and a new retaining ring. I have also had luck by simply removing the valve and cleaning the bore. Relube the orings and reinstall. Before you take the retainer out make sure you drain both sides of the air system or your going to have a funny purge valve looking mark in your forehead

  2. #2Water Doc2011-02-14 19:07

    http://service.mcicoach.com/serviceinfo/servicebulletins.nsf/656d2ee39f727cd386256c1e0042b975/bd8925b2ddb12ad786256fd400517d1a/$FILE/2902.pdf Theres some info on the valves. It's a coach website but perhaps some of the part numbers might lead to the updated kit

  3. #3digger242j2011-02-14 21:02

    It might be an improvement...

  4. #4Orchard Ex2011-02-14 21:51

    Thanks WaterDoc, I'll pull it out and clean it first chance I get. It'll go with the big muffler burn on my arm... or maybe knock some sense in?

  5. #5DiamondLTruckin2011-02-14 22:38

    Make sure and CHANGE YOUR FILTER. Ours was all sorts of gummed up and it turned out the filter hadn't been changed in 3 years :Banghead Considering that thier interval is supposedly every 12 months it doesn't surprise me that we ran into trouble. Its also a lovely experience when you get given the wrong purge valve from KW. Especially when you give them your VIN and even show him pretty much the exact pictures that you posted on here. Even more fun is my 1.5 hour drive to KW when I'm pissed off at the parts man. Not to mention that ours went out the coldest week of the year last year.

  6. #6rigandig2011-02-15 01:50

    One of my fall maintenance items. Change the dessicant filter. Every other year buy a service kit and change the purge valve. Sure helps stave off cold weather problems with the air dryer.

  7. #7CM19952011-02-15 01:57

    It'll match the snap binder birthmark..:cool2