No Air!!!

[rdbishop]

A friend of mine just purchased a 1975 MCI in Chicago and drove it to Austin, Texas with no pr0blems. He's gutted the insides and just took out the bathroom. He was going to drive the bus to the dump and get rid of all he had taken out but has no air. The bus fires right up but no air. He's  checked all the lines and Everything is clear up to the line going to the first tank . I think it might be the check valve at the first tank. He,s going to check that when he gets off work today. Has anyone else had this problem and what to do?

Richard

[Sam 4106]

Hi Richard,

The first place I would look is the air governor. I had a similar experience with our 1976 MCI 8. I tapped on the governor and the air built up normally. When we got to our destination, I replaced the air governor. No problem since.

Good luck, Sam

[rdbishop]

Thanks Sam,  I mention that to him, but he says the compressor is working fine. He also said he can air the system from the front aux. tank but not from the rear of the bus.

Richard                       

[Jnbroadbent]

If its nt compressor/gov/air dryer/purge valve, and if he can air it up from the front then sounds like a protection valve.

[Ednj]

There are a few air lines involved in the removal of the bathroom.
Did he reroute and cap off as needed?
There are also lines under the holding tank that sometimes get damaged during removal.

[Seangie]

Richard,

Compressor can be fine but I would still check the governor, also - make sure that the purge valve on the air dryer isn't stuck open.

-Sean


www.herdofturtles.org
1984 Eagle Model 10S

[Lin]

There is really a lack of information here. It would certainly be best for your friend to post everything he has done.  If it were such a massive leak that he can not hear the leak, he wouldn't be able to air up the system with a shop compressor, so he should be able to hear a leak.  How does he know that the compressor "is working fine"?  Has he already checked the governor?  How does he know that he has aired up the entire system through the aux tank?  Details would help.

[rdbishop]

Hi Lin, I'm sorry about the shortage of info but that's what I have to work with. The is on the MCI board and I told him to get on this one...He hadn't heard of the BCM but he knows now. He said everything worked fine until he took out the bathroom. After that, the bus starts and runs fine but nothing will air up, so the brakes are locked and no air bags, and no air pressure to the dash area etc.             

I think he may have a air line loose are capped that's not letting the gov. know what's happing. I'm just trying to give him things to check and maybe fix till the weekend when I can go there and put hands on.

Richard

[Lin]

Richard, it is understood that you are the middleman just trying to help.  I appreciate the situation.  It is just rather confusing to me.  Earlier it was said that he could air the bus through the aux tank.  Does that mean the accessory tank?  If he had been able to air the bus that way, then the air bags would be inflated, etc.

There are definitely people here that will be much more familiar with solving this problem than I am.  I am merely saying that in order for him to take advantage of that resource without depending on a lucky guess, good information is required.  Another thing that can be important is understanding the level of skill of the person doing the work.  When a person posts themselves, you often get a feel of what that is and answers can be tailored to that level.  For example, when he says that the compressor is working fine, it would be good to know how he came to that conclusion so one would know whether it is accurate or not.  With some people it would be superfluous to say the governor can be malfunctioning even if the compressor is good.  For someone else, that could be a vital piece of information. 

I would ask, is there air in the main tank?  If yes, it would seem the problem is downstream.  If no, it is upstream (compressor, governor).  He can check for air in that tank by opening the drain valve.  Even if there is a massive leak downstream there could well be a pulsing of air coming out of the drain as the compressor pumps.

[luvrbus]

Richard with a 1/4 inch air line not capped off they won't air up start flipping switches and see if it changes,in all the years I have owned a bus I remember having 1 governor go bad

[rdbishop]

 Thanks Guys, for all the good info. I'm waiting for A return call so I can pass it on...............