need help remembering where all my perge valves are

[Oregonconversion]

I found the one under the drivers seat outside, and the one under my dual tire. Where are the rest of them? Ohyeah.... any why do I need to get the water out of the air system anyways?

[bevans6]

On my MCI the tanks are behind the rear wall of the rear luggage bay, between the front wheels on the rear wall of the front axle bay (two of them there), and under the drivers seat.  On my bus, slightly younger than yours, the wet tank is the drivers side one between the front wheels, the parking brake tank is the other one between the front wheels, the dry tank is behind  the wall of the rear luggage bay, and the accessory/suspension tank is under the driver's seat.  There is a tank looking thing on the front wall between the front wheels that is the air dryer.

Bad things are done under the midnight sun when bus drivers don't drain their tanks.  The air gets all wet, the seals take a set, and the brakes say "slow down? No thanks"...

brian

[Nellie Wilson]

Hey, Brian -

Nice coincidence, you talking about air tanks. In cleaning out my bins, I noticed a recurring problem. My 'dry' tank ain't so dry as I'd like it to be... at least on the outside.

The compartment seems to just manufacture moisture. When I first got the bus, a good 3"-4" inches of mud and wet goop was on the floor, and the tank was rusted (but repairable). I chalked the moisture up to leaks, and sealed the floor and the wall (to the wheel well) with rubberized undercoating. And I drilled out any holes (corrosion) and installed either rivets or bolts (depending) to fill them.

But I'm still getting too much moisture in there. Since you have the same bus, wondering if you have that same problem?

Since I need to pull the panel to clean everything up, I was thinking of cutting some louvers or 'breather' holes into it. What do you think?

Thanks,

Nellie

[bevans6]

Hi Nellie.  My dry tank is always completely dry on the outside, and the compartment seems to be fully sealed.  There is just a tiny hole a little pipe that runs from the drain valve to below the floor, the floor is the same as the floor of the luggage bay, and the back wall (front wall of the rear axle bay, just in front of the drive tires) is fully sealed.  I would look for where the holes are and seal them, rather than create more.  My drain valve for that  tank is a tee-handled twist valve, and there is a tube extension to it so that the air that comes out is exhausted just below the floor onto the ground, not inside the compartment.  the only access I have is the tiny little door that you open to stick your hand in to twist the valve.  other than that, the compartment is riveted steel walls.

Brian

[HighTechRedneck]

The importance of keeping the air system dry inside is two fold as I understand it.

First, when moisture gets in it can corrode/rust components and then it can be a dangerous problem and an expensive repair.

Second, in cold weather, the water can freeze and block an airline and conceivably crack something as the water froze and expanded.

I recall last year at Jack's seeing the result of draining a wet tank on a bus that hadn't been taken care of in a LONG time.  Someone had bought it and brought it to him for some work on it.  I don't recall if it didn't have an air dryer or the air dryer wasn't working.  But it dumped a huge mess on the ground.

On the other hand, on my bus I have a well functioning air dryer.  It was a year and half and about 3000 miles after I bought my bus that I got it over a pit and first drained the tanks (no pull cords or even t-handles on mine, you have to get under them with a custom made wrench).  After all that, I got about a teaspoon of slightly oily water out of the wet tank and none out of the others.

[Nellie Wilson]

Okay, Brian -

I'll take your advice. Sounds like yours is sealed a lot better than mine. My front plate (the 'wall' with the 'tiny little door') is attached just with metal screws - obviously set up for easy access (looks like OEM, but who knows?). But I don't think that's the source of the moisture, because the bay itself is well sealed and bone dry.

But you gave me an idea. You say...

My drain valve (has)... a tube extension so the air that comes out is exhausted below the floor onto the ground, not inside the compartment.

I don't recall having a tube, just a drain hole in the floor? if it's gone, I'll install one. But I hardly ever drain that tank... and when I do, nothing but air comes out.  So that's probably not the source either.

Shoot! The never-ending mysteries, right? 

Hey, another question: Do you have a 'ping' tank drain (in same compartment where OEM plumbing resided)?

Mine occasionally doesn't purge. And the other day, some nasty looking gunk came out (but I'd recently squirted WD-40 into my unloader valve). Anything to worry about?

Nellie

[bevans6]

Ah yes, the mysterious ping tank.  It took me about three hours of thinking and playing to figure out why sometimes it purges with a nice blow and sometimes it just kinda sits there...  It is actually called the discharge muffler in the book, and the ping tank in the drivers manual 9I have both for the 5C, by luck).  Whenever the governor has told the compressor to stop supplying air, the air dryer purges and all the air in the line from the compressor through the ping tank  and up to the air dryer purges out the bottom of the air dryer.  So when you open the ping tank drain, nothing comes out (unless there is enough 'stuff' in there to just drip out).  If you try it when the compressor is in the middle of a fill cycle, the air dryer purge valve is closed and there is whatever air pressure the compressor has developed inside the ping tank and all sorts of air comes out, pulling whatever gunk has been captured and is in the lines with it.  If you remember BW's advice, you would normally try to turn the bus off when the air dryer purge valve is closed, hence the compressor is on a fill cycle, hence there is is air in the ping tank.

I honestly just sat there and spun in a circle when I first noticed that sometimes there was air there and sometimes there wasn't...  Your gunk was probably just soot and residue washed off the inside of the hose and the ping tank by the Stoddard solvent in the WD-40.  Nothing to worry about.  If you start to see oil and gunk coming out of the ping tank on a regular basis, start saving up for a new compressor...  it is designed to catch the oil before it gets to the desiccant in the air dryer.

Hope this help.  If I answered a totally different question to what you asked, sorry about that   

Brian

[Oregonconversion]

Great info guys!

Can someone give me a number of how many tanks I have on my 8
And where I can find all these tanks?
I need to make a list and be sure to get these.

[bevans6]

I'll edit my initial reply to try to make it a bit clearer.

On my MCI there is one tank behind the rear wall of the drivers side rear luggage bay, two tanks between the front wheels on the rear wall of the front axle bay, and one tank under the drivers seat.  On my bus, which is slightly younger than yours, the wet tank is the drivers side one between the front wheels, the parking brake tank is the passenger side one between the front wheels, the dry tank is behind  the rear wall of the drivers side rear luggage bay, and the accessory/suspension tank is under the driver's seat.

That is a total of 4 tanks.  Now: I think they are the same on your bus, but they may not be identical.  But I bet that they are close.

Brian

[Nellie Wilson]

From Brian: If I answered a totally different question to what you asked, sorry about that.   

Nope. You were spot on! Many thanks.

Nellie

[Ed Hackenbruch]

You are slipping Nellie.  You shouda said many tanks!

[Nellie Wilson]

Dang, Ed, you're right!

Missed a great opportunity for a sucker punch. Glad you got my back, pal!

Nellie