Cleaning out air system

[Chaz]

In my other threads, Dallas brought up a good point of cleaning out the air system.
OK, so how do you do that?? Is there a "flush" of sorts?? I know the tanks can be bled but what about at the air bags and other air using parts?? Would it be better to use shop air to blow thru as opposed to the bus's compressor?
So many questions, so little knowledge. 

I don't have a dryer, as Dallas recommended. Any suggestions on where to get a good, possibly used, one?? And what would be a good one to have?? (I'm such a rookie.  )
Chaz

[Barn Owl]

I don't think you need to incur the expense of a dryer if you only occasionally use your bus and you drain the tanks daily when in use. My compressor was worn out and putting a lot of oil in the system so I went with a used one. NIMCO was able to tell me at the time which one I could use with out mods. My system seemed to clear up on it's own without any special cleaning and is doing fine.

[Chaz]

Thanx Barny. I saw were Nimco had some used ones. I will look into that and also the Cincy place Dallas recommended. It would be nice if it did clear up on it's own but I was wondering if there might be some sort of cleaner I could run thru it and then drain the tanks or whatever. If not, I'm good with saving the work.  There are plenty other things that need done.  (paint, wall covering, bathroom vanity, shower, kitchen sink cabinet, new frige, flooring, and on and on and on...............       )

I don't use it much in the winter altho it's a goal to. I want to eventually get outta here and to the warm south for winters. So if I can come across a good dryer for a good price I'd snag it up.

Thanx again!
   Chaz

[bevans6]

"cleaning out the air system" is  probably a euphemism for repairing all the damage that has been done by the oil coming from the air compressor.  That could mean as little as draining the wet tank a few times to replacing all the seals and valves that have been ruined by the presence of oil, along with putting new brake cannisters on, and so forth.  From what Dallas wrote, your air system is losing air at a ferocious rate, 15 PSI in three minutes on the brake test when 3 PSI is the legal limit for operation.  You need to figure out what is wrong and fix it after you get a clean compressor on.  I honestly have no idea how you would go about getting the oil out of tanks and lines.

Brian

[JackConrad]

  From what Dallas wrote, your air system is losing air at a ferocious rate, 15 PSI in three minutes on the brake test when 3 PSI is the legal limit for operation. Brian

Loosing 15 PSI in 3 minutes during the brake test would indicate a significant leak in the service brake system, not a weak compressor, since the engine is not running during this test.  Jack

[bevans6]

Yeah, completely agree and I didn't mean to imply otherwise.  the leak down tests for the whole system and for the brakes are always with the engine off.  15 psi in 3 minutes is a monster leak.  It could be as simple as a leaking quick release valve or as hard as new brake cannisters or relay valves or lines.  Of course, if the whole system is leaking down that fast, then the brakes might well be fine and the loss on a brake test is really the loss overall.  But my bus has a series of check valves that separate the brakes from the rest of the system.  Bottom line is there are a number of things that could be wrong, and the whole system needs to be looked at, evaluated and fixed.

Brian

[Oonrahnjay]

Loosing 15 PSI in 3 minutes during the brake test would indicate a significant leak in the service brake system, not a weak compressor, since the engine is not running during this test.  Jack  

Jack, if I read Dallas's comments right, the system has multiple problems -- including a significant leak in the service brake system and also a weak compressor.  Apparently, when no air is going to service brakes, it still takes a long time to build up air pressure (engine running).  IMO, that system needs a top-to-bottom check with all the little detail problems dealt with.

[Oonrahnjay]

@ Brian - Great Minds Think Alike!

[Tim Strommen]

...I honestly have no idea how you would go about getting the oil out of tanks and lines...

Just a guess, remove valves and devices (brake caniters, tanks, etc), flush each line with Simple-Green or Dawn mixed with hot water.  Flow until "clear", then chase with dry nitrogen until the line stops "spitting".  Valves and devices should be taken apart and damaged rubber components replaced (obviously).  Everything else (metal parts) should go through a parts cleaner, then dried and re-assembled.  Tanks would need all the ports plugged save for one then repeatedly filled and agitated with a Simple-Green or Dawn and hot water fill until the drain water looks "clear".  Then flushed with dry nitrogen and baked for 24H @ 100C to ensure it's absolutely dry.

Simple-Green and Dawn dish soap are grease/oil-displacement chemicals, which break the surface tension bond - the hot water acts to carry the contamination away and helps keep the oil flowing by being warm.

If you're going to go through that trouble, put an air dryer in if not already equiped - if you had one in there already, most of the oil wouldn't have gotten past the dryer and you wouldn't be suffereing so much with the cleanup...  They aren't that expensive - I found a rebuilt AD-9 on the e-place for $100, and if you aren't running that many miles per year, it should last for a good long time.  

-T

[JohnEd]

3 problems.  Oil in lines due to compressor seal failure.  Leak in the system that is so bad it should be easy to locate.  "all" the seals that have gotten oil on them will fail if the "O" rings and other seals are affected by oil.  That.s a lot of stuff.

First R&R or rebuild the compressor to stop the leak.  Then go after the leak.  Get pro advice on the air valves and controllers about their being ruined by oil.  It isn't always so and some stuff has Viton rubber seals and it will stand up.  My guess is that you will spend a lot of time disassembling those air system components and replacing "O" rings....emphasis on "my guess".

Paint thinner, aka mineral spirits is a pretty benign solvent.  Good for rubber I don't know.  But it is cheap and cuts oil really well.  Seeing as you might be taking down the system it shouldn't matter much what solvent you use if you use it BEFORE you rebuild stuff.

If you don't have an air dryer you have a grounded vehicle in the winter or any place you go where it might freeze regardless of the season.  

Good luck with this Chaz. I am sure you will "get'er done"

John