Shop air attachment? MCI-9 location

[grantgoold]

Have a 1984 MCI-9. Can anyone show me your shop air hook up location.  I have what I think is the site but having trouble getting any air to enter the system.

Thanks

Grant

[Dave5Cs]

Grant if you open rear right hand door look to the front bulkhead. There should be the bigline from the top or side of compressor. There should be a sign that says "Drain Daily " with a down arrow. At the end of that tub there should be a drain . Leave the drain and put a Tee in there and then your NPT fitting.
Dave

[grantgoold]

Dave, I have placed a fitting on the top end of that valve. I have opened that valve and tried to get air into the system.  No luck.  I have also noticed that according to the maintenance manual there are some emergency fill valves in the front of the bus on the drivers side where some keep their tools.  I will try those spots as well.

Thanks

Grant

[bevans6]

The emergency fill just sends air to the emergency/parking brake tank.  If air bleeds into the rest of the system then the check valves that isolate that tank/system have failed.

The ping tank "drain daily" port is what I use.  It goes through the air dryer, which is a good thing.  If no air is getting in then the "drain daily" wasn't drained for few years/decades, and you need to take that little tank apart and clean it.  It is the main feed separator from the engine air compressor to the air dryer and on to the wet tank, so air must be able to get through there.  I also put an air chuck on the auxiliary tank, but it is an air output, not an air input.

[Jim Eh.]

Before working on a pressurized system (always assume the gun is loaded) dawn some safety glasses.

If you use the one these guys are telling you to use then you will automatically know when your system is full as the dryer will purge signaling the system is full.

[grantgoold]

Good safety advise for sure!

Thanks

Grant

[Dave5Cs]

Grant also when cleaning the ping tank take the big hose off and look through it to make sure it isn't full of crap or you won't get much air through the system if any.
I also put a fitting under the dash where I took off the air dump valve with the little red ball on it but I don't have the door claw anymore so don't need it.. That way I could hookup when air dryer was not closing which did happen and filling there allowed me to air up and release brakes. Using my on board shop air to get it off the road to fix or bi-pass the air dryer until I could fix it.
Dave

[buswarrior]

In your MCI, if you attach your aux air to the discharge muffler drain inside the curb side engine access door...

You still need to leave a way to drain it.

One of the biggest winter time disabling freeze up places, after, and contributing to, an air drier with missing or failed purge valve heater.

Unwittingly pushing moisture past the air drier is a very real scenario.

Air driers have a finite capacity to remove moisture, after so many cubic feet of air, it's ability to condense and remove moisture is gone, and the moisture continues into the system. That's why it purges after every cycle in normal operation.

Picture a busnut, running an aux system pump for whatever air consuming purposes while camping.
Was the discharge muffler drained on arrival at the camp ground? Frequently, it starts full, so no capacity left to catch moisture.
The air drier then has it's capacity of air volume pushed through it over the camping time, and reaches the saturation point and beyond.
Then it's time to leave, early some damp, dew covered morning, and some combination of the aux air and the coach air compressor fill the entire system, pushing more moisture laden air through.
Finally, on reaching cut-out pressure, the air drier purges it's overload of moisture.
But the discharge muffler is still full of water...
And the cycle continues.

Every cold snap, every winter, busnuts come screaming on the boards about air system freeze up, and parking brakes locked on.

All that rogue moisture goes deeper, affecting whatever air valves it can reach. The slightest lick of moisture on a seal or seat will render an air valve non-functioning. That moisture must be caught and removed before it gets sucked deep into the system.

Self inflicted wounds? Is that still a punishable offense?

Drain the discharge muffler regularly, and, air drier or not, drain your air tanks regularly, and WATCH to see what comes out.

Discharge muffler is going to blow moisture and oil.
Air tanks should blow nothing but air with a good air drier.

24/7/365... enjoy air system functionality in the cold, or...

happy coaching!
buswarrior

[Dave5Cs]

BW if you are talking to me about that last post bipassing it was a was a temporary thing so I could fix it. Just needed a purge rebuild. I have an AD9  air dryer. And I have a drain below where the NPT fitting was teed in. So I drain frequently when on the road and leave the drains open through the summer so they can really drain if needed.
Most people go around and pull the drain cables if they have them and only for a few minutes each. They sometimes don't drain at their ping tank but should. when there is full air in the system and you pull the chain so to speak if there is moisture and or oil in that tank the air go flying through it and very little comes out. Eventually you have a tank full of stuff, water oil and rust. Leave it open at a lower pressure to really drain them well.
Dave