Using the bus as an air compressor.

[gumpy]

Craig,
   You may be correct.  My MC-8 is an early one ('73) and I know MCI made some changes in tank locations. Is your air dryer in the front or rear of your bus? I think it is usually close to the wet tank. My dryer is in the rear along side 2 air tanks.  Jack

I think you are correct that the dryer is near the wet tank (funny terminology, the air goes through the dryer first and then into the wet tank. Why do they call it a wet tank if the air is dry? And if the air isn't dry when it enters the wet tank, what good is a dryer?).

On the MC9s (at least the one I have, and the one's I have seen), and the later MC8s (mine was a '78) the air dryer is in the front and there are two tanks up front behind the front axle and one tank in front of the rear differential, center of the rear bay wall.

craig

[DrivingMissLazy]

I was under the impression that many of the earlier buses (see BK I can spell it correctly) did not have a dryer. That was why the tank had to be drained daily.
Richard

I think you are correct that the dryer is near the wet tank (funny terminology, the air goes through the dryer first and then into the wet tank. Why do they call it a wet tank if the air is dry? And if the air isn't dry when it enters the wet tank, what good is a dryer?).
craig

[gumpy]

I was under the impression that many of the earlier buses (see BK I can spell it correctly) did not have a dryer. That was why the tank had to be drained daily.
Richard

I think that's true. I don't think dryers were common on buses until sometime in the mid to late 70s, but it may be earlier than that when they started putting them on. I think it was initially introduced as an option, and eventually became standard equipment. I think many that were built without one had one added later on.

[Steve]

I have a '70 mc-7 that has a small spring loaded door on the passenger rear, just above the side access door( original a/c access door) that housed the "potable water fill connector" for original bathroom. I removed the water fill connector and plumbed in a female quick connect for air by tying in to a valve just below that door, inside the engine compartment(approx 20" of dot hose). I also plumbed in another female quick connect in the tank under the driver's compartment, where I have a 110v compressor mounted for air-up before starting the DD. There is another small, hinged door in the access door for that compartment that housed(past tense) the receptical for supplying 110v power to the bus while stopped at the greyhound terminal, which,in the near future will house the air coupler for that corner. I hope this made sense,  Steve

[Buffalo SpaceShip]

My '78 4108 has no air dryer, but does have a moisture ejector valve on the wet tank that takes care of most of the condensation. We don't have much moisture in the air out here in CO anyways.  Nothing ever seems to come out of the dry tank, the rear tank, or the aux. tank. I also have the alcohol tank on my compressor, but don't bother with it during the warm months.

I have noticed quite a bit of oil coming out with the water in the discharge line, esp. compared to the 4106 that just expelled the water. So, it's probably time for a rebuilt compressor. I'll likely add an AD-2 or similar when I do. They seem cheap enough.

Brian Brown

[pvcces]

Brian, from all the reports that I have run across, it will pay you to go up to at least an AD-4. The AD-2 costs too much to maintain to make it worthwhile. There is even a newer unit recommended for motorhomes, the AD-9. Very easy to service, but pricey.

For what it's worth.

Tom Caffrey
Suncatcher
Ketchikan, Alaska

[Buffalo SpaceShip]

Thanks for the heads-up, Tom. I'll look into the newer units, for sure.

Brian