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Bus Discussion => Bus Topics ( click here for quick start! ) => Topic started by: scott332 on May 12, 2010, 05:37:32 PM

Title: Air pressure regulators
Post by: scott332 on May 12, 2010, 05:37:32 PM
I am starting to chase down air leaks on my MC12.
I am working on some air pressure regulators that are leaking around the diaphragm.
Is there supposed to be air constantly coming out of the small hole in the cover?
I have 2 regulators in the shop that I'm working on.  One leaks air out of the hole, the other one does not.
The parts manual has 2 different part numbers for air pressure regulators, but does not specify what the difference is between them.
Title: Re: Air pressure regulators
Post by: Melbo on May 12, 2010, 05:39:51 PM
No the air regulators should not leak  --- I don't know the difference between the two different part numbers.

HTH

Melbo
Title: Re: Air pressure regulators
Post by: zubzub on May 12, 2010, 06:19:34 PM
If they have flat diaphragm Dallas has a link showing how to rebuild them using silicone sheeting.  worked for me.  Saved a few bucks and singlehandedly saved the planet
Title: Re: Air pressure regulators
Post by: bevans6 on May 13, 2010, 05:36:00 AM
all of the regulators on my bus are Williams WM-279-E1.  They just block the flow of air over a certain pressure, adjustable with a spring preload screw.  No leaks allowed, anywhere.  I got a rebuild kit from Luke that worked fine, it replaces the whole insides not just the diaphragm, and I bought a spare new one to carry around to guarantee that none of them ever fail again...   ::)

Kit was cheap, new unit was less so, but I have this theory that if something breaks the other ones are close, so I like spares.  If you go on the Williams website there are data sheets for each model, and there are a ton of different models.

Brian