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Bus Discussion => Bus Topics ( click here for quick start! ) => Topic started by: Lin on March 26, 2008, 06:14:03 PM

Title: Low Air Pressure switch replacement
Post by: Lin on March 26, 2008, 06:14:03 PM
I need to replace the Low Air Pressure Switch but found that the MC-5 one costs about $140.  It seems that any one that is normally closed would work.  Any suggestions on where to get one?
Title: Re: Low Air Pressure switch replacement
Post by: compedgemarine on March 26, 2008, 07:43:45 PM
I would think any heavy truck parts house but you would probably need to know the pressure that opens it.
Title: Re: Low Air Pressure switch replacement
Post by: JackConrad on March 27, 2008, 05:27:53 AM
We went to a truck parts place and purchased a switch. The switch was preset to open at 65 PSI. I don't remember the price, but I am pretty sure it was less than $25.00.  Jack
Title: Re: Low Air Pressure switch replacement
Post by: buswarrior on March 27, 2008, 12:01:56 PM
Lin, does the one in your MC5 mount to the junction box in the back and also control the alternator?

You may have to be careful that the rest of its functionality is maintained or otherwise modified, if you still have an air tensioner for the alternator belts.

happy coaching!
buswarrior
Title: Re: Low Air Pressure switch replacement
Post by: FloridaCliff on March 27, 2008, 04:43:00 PM
Lin,

At least run it by the local truck parts jobber first.

Many, many times I have saved a small fortune by seeing if they have something that will work from another application.

Cliff
Title: Re: Low Air Pressure switch replacement
Post by: Damn Yankee on March 27, 2008, 05:08:09 PM
16.00 ea. at eb** #230073827660 All thats wrong with your switch is the diaphram inside leaks. When my brake light switch started leaking I removed the diaphram from one of the low pressure switches I bought and installed it in the BL switch. Worked like a charm.

Bob
Title: Re: Low Air Pressure switch replacement
Post by: Lin on March 27, 2008, 11:02:55 PM
I have ordered a Bendix lp-3 type low air pressure switch from Napa for about $25.  It seems that it should work with a small plumbing adaption.  Although it seems odd to me, several of the truck supply places I called said they only had the air pressure switch that is normally open.  Whether the switch is supplying current or ground it would be normally closed.

Bob, thanks for the ebay listing, but we are leaving for our new home is Joshua Tree on Sunday which is about 500 miles away, and I wanted to have this done before then.
Title: Re: Low Air Pressure switch replacement
Post by: FloridaCliff on March 28, 2008, 03:10:46 PM
Quote from: Damn Yankee on March 27, 2008, 05:08:09 PM
All thats wrong with your switch is the diaphragm inside leaks.
Bob

Bob, I totally agree!

I was soooooo aggravated when I couldn't find just the diaphragm for mine.

But I kept the old switches in case I find a source....

Cliff