removing air bag bolts

someguy · September 04, 2020, 01:08:00 PM

Quote from: chessie4905 on September 04, 2020, 10:11:43 AM
Someguy' the air bag bolts have a partially rounded head with a bump on the underside to keep it from spinning when you install and tighten them. Old rusted ones spin the head within one or two turns.

Carriage head bolts and the square shoulder is rotating in the housing ? Tack weld the head so it can't rotate.

A picture would really help us help you.

chessie4905 · September 04, 2020, 02:32:57 PM

it is not a square shoulder. it is a 30 to 45 degree angled slightly rounded head with a small bump on one place.

someguy · September 04, 2020, 04:01:20 PM

Quote from: chessie4905 on September 04, 2020, 02:32:57 PM
it is not a square shoulder. it is a 30 to 45 degree angled slightly rounded head with a small bump on one place.

Can you tack weld the bolt until you get the nut off ? Or sheer it with a chisel.

I'd love to see a picture of this bolt.

benherman1 · September 04, 2020, 04:56:40 PM

These pictures show the before and after of removing them. Welding the heads to the ring would be a pretty bad idea unless I want to make a bunch more work for myself or have to buy new rings. You can see the tops of the bolts in the ones laying around the loose bags.

I just got home from getting the air chisel. I may or may not decide to try it tonight depending on how lazy I decide to be. I also have a pretty decent cold chisel and a 4 lb sledge that I usually use to break up whats left after my cutting on the nuts. I could try sharpening it up and skipping the cutting.

lovetofix · September 04, 2020, 07:58:16 PM

Absolutely second the air chisel. I took off most of mine that way at about 10 minutes per bellow. Don't try to loosen the nut, it will just make it spin.
The lower ones you can get at from the bottom, try cutting the nut straight up inline with the bolt, then they can't spin. The nuts were very soft on mine and would spread enough from one cut to fall off.

Jim Blackwood · September 05, 2020, 08:47:24 AM

The same idea of re-grinding the chisel tip would work on the air chisel also, reducing the angle by half will make it cut four times faster. It's a good bit of grinding but I've always found it worthwhile. If you like you can grind a shallower angle on the very tip to make the cutting edge last longer.

Jim

Ed Hackenbruch · September 05, 2020, 09:02:38 AM

If you look close you will see that even though the bolts can go in either way, one way the heads conform perfectly to the curve of the ring and the other way it sticks out a bit....make sure when you put it back together that they conform to the curve or they will start leaking after a while. Only use the bolts made for that......stove bolts, carriage bolts, etc. will leak. A while after i bought my bus a found that i had an air leak and it was one bolt that had been put in facing the wrong way.

chessie4905 · September 05, 2020, 11:30:58 AM

Good point Ed. They can be easily mis-indexed if not careful. Note where the recess for the bump under bolt head is before inserting. Also make sure they dont rotate when tightening. Ad neverseize to the threads in case you need to take apart in future. They make a longer bolt if you need to use block off plates.

Ed Hackenbruch · September 05, 2020, 06:06:57 PM

When i first heard one of my airbags leaking the second year that we had the bus, i felt around until i could feel the air leaking on the back side of it. My first thought was that somehow a sharp rock had gotten between the bellows and worn a hole in it. I was really surprised after i pulled the wheels to get to it that it was just a bolt that had been put in wrong. Since i had ordered new bags, rings, and bolts, i just replaced them all and kept a few of the better old ones as spares, which i never needed in the following 10 years that we had the bus. As a footnote, i did all of this while recuperating from a dislocated shoulder......learned to move really slow and think about how i was going to move wheels and jacks and cribbing and a lot of little things like reaching behind you to grab a tool......did all this during the 2nd month of healing, took me 7 months to completely heal up to where i could do things like i had done them before. Found out it takes longer to heal as you get older!

benherman1 · September 05, 2020, 06:16:31 PM

I've been getting my bolts and bags from Luke so no problems there. I had just finished bag 2 and was getting started on bag 3 when I started this thread so the crash course parts are over at least. I'm pretty jealous of the buses where re-using bolts is an option on the bags. I wouldn't be surprised if the ones on there were factory installed from the way they look. One had a bad leak on the way home. You would have to block the bus before turning it off to give you an idea. I had to be careful with my braking to make sure I didn't run the air down too fast. The ones I'm doing now actually hold air fine but are de-laminating the inner and outer layers and the outer part was expanding like a balloon. I figured I'd rather do them now and be done with it than wait and see if I end up doing one on the side of the highway...

dtcerrato · September 05, 2020, 06:44:42 PM

The mention of & seeing photos of some of the air bellows - de-laminating & ruptures causing bubbles can be caused by oil, grease, or any petroleum being slung on the air bag. A good example is where a rear bag is adjacent to a universal joint. A simple shield of any sort will protect a new bag from this issue... We've put them is a couple places.

benherman1 · September 05, 2020, 07:05:26 PM

Quote from: dtcerrato on September 05, 2020, 06:44:42 PM
The mention of & seeing photos of some of the air bellows - de-laminating & ruptures causing bubbles can be caused by oil, grease, or any petroleum being slung on the air bag. A good example is where a rear bag is adjacent to a universal joint. A simple shield of any sort will protect a new bag from this issue... We've put them is a couple places.

The rear pair actually have shields already. They looked dry but I wouldn't rule it out. I'll have to keep an eye on it after I get it on the highway he first time and see what gets wet. It would be pretty easy to fab some more shields and just attach them with the extra threads on the bolts. I'm hoping in this case it was just age. Pretty much everything rubber is in similar shape. I also just replaced all the air brake lines and the foot valve for similar reasons. I was able to snap some of them in half by hand.

someguy · September 06, 2020, 11:48:05 AM

The rubber used on air bags is impervious to petroleum products.

lostagain · September 06, 2020, 12:07:14 PM

I would agree with Someguy here. My rear bags get splattered with grease flung from the drive shaft Ujoint and it hasn't hurt them in the many years they have been there.

DoubleEagle · September 06, 2020, 01:02:43 PM

Going by chemical resistance charts for various kinds of flexible products, petroleum products under 250 degrees F are not recommended to be on rubber products other than ones such as Nitrile, Hypalon, Silicone, or Viton. From what I have seen, airbags are generally made of a combination of natural rubber and polyurethane. Grease might have less affect than oils, but I suspect that over time exposure to splashed oils would have an effect. I don't think it is accurate to state that airbags are impervious to petroleum products, rather, they may be resistant to oils (and ozone) to some extent.