Air beam woes

Chopper Scott · April 24, 2009, 06:08:11 PM

I'm so glad I have spent basically the last 6 months scouring this forum and learning from experience that is offered here with my MC 7. My first leak was the 65 pound air regulator for the front bags and it arrived yesterday from Mohawk. I went to the storage unit and the ole girl fired immediately and I headed for my shop. It leaked bad enough that it wasn't long before the bags were empty and before I had it blocked up I could change it. Pretty quick and simple fix. I hooked up the air to the shop compressor and filled her back up and for the first time I had an air leak in the back. Further investigation found a spot between the drivers and the tag just below the floor and just in front of the support for the rear tag. I am sure many of you are already well aware of the spot!!

Sometime in it's life somebody got creative with the JB weld and tried to fix it but it failed. Owning a welding business I get a lot of challenges like this from time to time. Basically I ended up with a pretty good sized hole but found good metal. As the leak was also somewhat in an area that couldn't be reached it required an inside out type weld to repair the top of it. After filling the system back up I had a few small bubbles show up when I soaped the repair but now the bags don't leak down in a matter of minutes and I'll have to wait until tomorrow morning to seal it up once and for all. I'm just glad the front stays up now. Hopefully the rear will follow suit! I just want to thank you all for all the things I have learned just by reading posts and doing searches. Knowledge and experience can't be beat and when it's free like here it's something else. Thanks all. Later

Hi yo silver · April 24, 2009, 07:23:36 PM

Doncha love this board?!
Dennis

Airbag · April 25, 2009, 04:32:28 AM

Hi Scott
Please if you don't mind sharing some details of the repair, what was the cause of the leak, corrosion or a crack? What welding process was used, T.I.G , M.I.G , Gas? My front bags leak down in a days time and just figured it to be normal for most pictures of these buses I see the bags are flat.

I have seen a kit that takes the air beams out of the system using plates between the bags and the beams. I don't know but it would seem one would lose some cushioning effect by doing that.

Glad your up and running.

Chopper Scott · April 25, 2009, 05:02:04 AM

Airbag, Actually I migged and stick welded the hole shut. Stick welding does a better job of sealing versus mig on surfaces that are not clean. But mig does a better job of filling a hole so I used both methods. The reason my fronts leaked down was because of the 65 lb valve that I replaced. Later

oldmansax · April 25, 2009, 05:53:21 AM

The PO had already plated over the air beams when I bought our bus. I would like to repair the beams because I think the ride quality has suffered, however, it seems to be a daunting task if you are using the bus full time. I think Jack Conrad has the rolling lobe conversion which does a better job.

TOM

buswarrior · April 25, 2009, 07:47:58 AM

Trouble with air beams...

the leaks are often on top, between the beam and the plywood floor.

If a careful, and aggressive, inspection of the beams and towers proves they are structurally sound, the rolling lobe conversion would be far easier and produce the results you seek.

If the beams need welding work to restore their strength, time to flip a coin? To ensure the tops are tight, the floor has to come out....

There's a reason those plates were invented!

happy coaching!
buswarrior

JackConrad · April 25, 2009, 09:38:48 AM

Quote from: oldmansax on April 25, 2009, 05:53:21 AM
The PO had already plated over the air beams when I bought our bus. I would like to repair the beams because I think the ride quality has suffered, however, it seems to be a daunting task if you are using the bus full time. I think Jack Conrad has the rolling lobe conversion which does a better job.
TOM

Our bus had the block-off plates on the rear axle when we got it, so I cannot comment on the OEM ride. But, I can tell you the rolling lobe bags made a world of difference! Jack

RJ · April 25, 2009, 11:57:47 PM

FYI -

GM use air beams on the very first air suspended coach, the PD4104. Built them that way from 1953 until 1960.

Starting with the PD4106 in 1961 until they completely sold off the bus building division in 1986/7, they used rolling lobe air bellows in their suspensions.

Rolling lobes are the most common type in use today, both buses and trucks.

DIYW. . .

Chopper Scott · April 26, 2009, 06:57:50 AM

Well I got the leak stopped and I'm sure it will be fine for the time being but one has to be a realist and figure that eventually the corrosion will show up somewhere else and begin a new leak. I have a couple of bags that are getting weather checked also and someday will need some attention. I do believe I'll be taking Jack's advise and investing in the plates and rolling lobe bags in the foreseeable future but as of now I have many other areas that need addressed. I have to admit that unless you have some mechanical skills I wouldn't advise owning one of these ole girls. Later

johns4104s · April 26, 2009, 12:46:07 PM

my MCI 9 has many systems and parts the 4104,s have. i.e. Air bags,brakes drums,bearings etc.

those 04,s sure were engineered well.

john