MCI 8 Air System

[Sam 4106]

I would like to tap in to the air system on our MC 8 with a 1/2" quick coupler to run my 1" air wrench. The most logical place was the accessory air tank below the driver, but there are only 1/4" ports in that tank. I looked at the rest of the tanks and didn't find an easily accessible 1/2" port anywhere. Any suggestions?

Thanks, Sam

[Dave5Cs]

Sam
Mine is in the back side door passenger side where the big compressor line come over to the down pipe that says "Drain Daily". HTH

Dave5Cs

[Boomer]

If you're thinking of changing a wheel forget it.  The bus tanks are not large enough to run a 1" gun.  BTDT.

[bevans6]

I tried once, for fun, and I got about three hammers out of my 1" gun before it kind of sighed and gave up.  There are two logical places to add or remove air from your bus system.  I add air at the "ping" tank, also called the discharge muffler, which is the "Drain Daily" piece of pipe with the main hose from the compressor running to it mounted on the engine bay wall.  You can extract air there as well but it's not connected to any tanks that you can pull air from since there are check valves in place that prevent that.  If your bus is running and the compressor is on a charge cycle there will be lots of air there coming directly from the compressor, but if the compressor is on a wait cycle (air dryer has purged) then there is zero pressure there.  I have a quick-connect fitting tee'd into the drain of the ping tank.  I take air out of the accessory tank with a quick-connect tee'd into the drain valve.  The accessory system has the benefit of having air that has gone through the air dryer and the E-filter so it's clean and dry, and you have the tank capacity of the accessory tank, the dry tank and the wet tank to pull from as long as the pressure is above 65 psi.

My 1" gun is pretty frustrating.  The only thing that can run it is a 1/2" air line into my 80 gallon air compressor.  It won't run on a 3/8" line and it won't run off any of my portable compressors.  My neighbour had a Snap-on that he said was designed for 3/8" air lines but even that one really needed the big tank to run.

Brian

[Sam 4106]

Boomer,

Yes, I want to be able to R&R a wheel if I have a flat tire. I have been hauling along a portable air tank with a 1/4" input and a 3/8" output. I use a 5 foot 3/8" hose to the impact wrench and a fifty foot 1/4" hose from the bus accessory tank. I can remove a lug nut or two and then wait for the pressure to recover. It is slow, but better than waiting hours for a tire service truck. I recently got 65' of 1/2" air line from a surplus store and don't want to haul the portable air tank any more because it takes too much room.

Dave,

I thought about tapping that line, but, as Brian points out, there is air there only when the compressor is building air.

Brian,

I think my best option is to weld a 1/2" fitting onto the dry air tank (larger than the accessory) and run a 1/2" line to the area of the accessory tank. After reading many of your posts about the air system, I spent a lot of time studying the air system diagram for my MC 8. To make it easier to understand and follow the various lines I used several different colors of markers to identify them. That makes the system clearer, at least for me.

Thanks all, for your thoughts, Sam

[bevans6]

The dry air tank is the service tank for the brakes and really should not be screwed around with.  Play with the accessory system - sure, but I really would not be welding fittings and running random lines with quick connect fittings off the dry tank.  The dry tank is protected with check valves and the pressure protection valve so that it is protected from failures outside of the braking system, and your new fitting and line would compromise that.

FWIW, etc. JMHO and other acronyms.... 

Brian

[Sam 4106]

Brian,

Thanks for the warning. I will stay in the accessory area. I was a certified welder and have experience welding on pressure vessels so the welding wouldn't be an issue, but the possibility of the added air line bursting or leaking is real. I would place a ball valve between the air line and the quick coupler, so the coupler wouldn't be. I'm not concerned with moisture in the air because it is unlikely I will ever use the air source and I keep the impact wrench well lubed.

Thanks, Sam

[RickB]

Sam about the only way I could get that to work was to have a 20 gallon aux tank with a 1" line on it. You only need 8-10 feet of the big line it just needs to be able to reach the gun with as little hindrance as possible. Not sure if using a 1" line from the bus air system would work or not without the aux tank. Those guns use alot of air.

Good luck and you and the wife better come visit soon. I'll wear a bib around you 8v92. Wouldn't want drool all over your bus!

Rick

[sledhead]

Sam    When I installed my air leveling system I added an extra 20 gal air tank in the 1st bay for extra supply .Added to the accessary air with a one way valve and put a female 1/4" quick connect on the tank for a air line to fill a tire . It's not fast but it will do the job. So with a large enough supply tank anything is possible                          dave

[Red Rider]

How about a 3/4 electric impact that would plug into your generator?

[Sam 4106]

Rick, the 1" Chicago Pneumatic impact wrench works fine on the 3/8" air hose from the portable tank, but slow because of the volume of the tank. I can live with slow. I can use the impact off my 21 CFM 80 gallon shop compressor at 125 PSI and 1/2" hose on all 10 lug nuts without stopping. I have used it off a small pancake compressor and portable tank, but that was really slow. Anyway, it gets the job done.

sledhead, my portable tank is in the 5 gallon range. The only easy place to store it is preventing me from adding a sewer water drain valve to the passenger side of the bus, which is something I could have used a few times. That is why this project started. I will find a workable solution without the portable tank. Or find another location for the tank.

Red Rider, your suggestion would work, and I probably could run it, with the bus at fast idle, from the 4000 watt inverter or the 15 KW generator. But, I already have the air impact and would like to use it if I ever have the need. When we had the blowout, on our second trip with our current bus, I had no spare. I had to find a shop with a useable tire, willing to change it, and dispose of the old tire. That cost $240 and lost time. I decided then that I would carry a spare and the tools to change it, if the need ever arises again.

Thank you for all the input, Sam

[Ed Hackenbruch]

I have a 1/2" Ingersoll Rand gun that i use to take my wheels off. Works just fine if they are at the proper torque setting. I carry a portable compressor with me, fulltime, and only have two bays so space is limited and precious. Wouldn't travel with out it.