air dryer leaking

[Larry B]

hi everyone--- My bus has performed flawless for the last four outings starting to fell good about my efforts and the results. On next outing we had a little hickup. After fresh water and fridge loading when I started bus it would not air up. the bottom outlet of the air dryer was passing air. After a couple of hours of fiddling and manual reading I find that regular maintenance and yearly cleaning should be done. By giving the bottom block of the dryer a couple of good taps with a hammer, what ever was stuck open closed and it air up , so back to my shop. During original conversion I removed original heating and ac stuff. This gave me a lot more space in front bay so in my wisdom I decided to move the air dryer and wet tank to this space because I was having a hard time getting my chubby old body in that front axle area. Plus this gets my tank and dryer away from natures elements and rusting. Not all the choices I make are good and I am not sure where this one falls. From reading the manual I am getting the impression that inspection or cleaning can be done by removing and installing the internals though the bottom of the air dryer and leave the canister in place. Am I understanding that part correct? The main canister does not have to be removed. As you can see by the picture I now have a floor below my dryer, but I can soon make a bolt in inspection cover in the floor. To remove the complete canister from its new location is going to be awkward now.  The 3" square tube you see in the picture is the support for my slide. There is so much to learn abouit these units. Thanks   
          Larry B     

[Dave5Cs]

Larry the bottom has to be removed 4 bolts and there is a large rubber o ring that then is held in place by a large snap-ring. The heater is attached to it also. The purge valve in the center of it was what was stuck opened when you heard the leak. It is easy to replace but get the hard ball not the soft rubber one. Just get the whole rebuild kit, NAPA has them or MCI , Luke etc. There is a desiccant cartridge you just pull out the old one and replace it. There is also a check valve on the side upper line where it threads onto the dryer and another one inside the bottom plate. They are easy to rebuild 30 - 45minutes after it is out. Careful with the heater do not open it up or you will be buying a new one, just unscrew the wire on the outside of it. don't ask me how I know!.... HTH
Might be a good time to upgrade to an AD9 with a spin on cartridge also.

Dave

[luvrbus]

You have a AD2 dryer it has a large snap ring you pop out with a screwdriver were the flare is on the bottom of the canister  should have a couple of 5/16 safety bolt with small clips to remove but they are not always there fwiw.It doesn't look like you have enough room to remove the desiccant cartage without removing the drier that is a long winded sucker. 

You could upgrade to a spin on but there is no need those are good old dryers and easy to service compared to the AD9 with all the bolts no more than the dryer needs servicing you have ask it is worth it for a newer dryer JMO 

[Larry B]

   Cut a hole in bay floor and removed dryer internals today, now I have a couple more questions. I did not find what I would consider any large amount of oil or water in the dryer (2-3 teaspoons) but I did find gritty substance like sand sized pieces. I took some of this grit placed it on a piece of plywood and you could easily crush it with the back of you fingernail. I beleive the particle are carbon. Never having taken a dryer apart after been in service (at the most 10,000 miles).Is  this grit normal? Is this coming from my air compressor? Do I have some more searching I should be doing?  My air compressor was changed out at engine rebuild (10,000 miles ago). Normally when I blow down any air tank in the shop on a concrete floor I notice no amount of oil or water. You are right Clifford it is an AD2. Do most just automatically change dessicant when you have dryer apart? This grit would pick up with a magnet before and after crushing. Not a very stronge attraction but some did pickup. With this grit under the exhaust valve I can understand it not sealing. Thanks for all the guidance.
          Larry B

[luvrbus]

Somebody didn't change the supply hose which one is supposed to do when changing the compressor and I would change the dessicant since you have it a part

good luck