Replace an Air Bag

[MangoMike]

I just replaced one of my front bags. Here's the HOW TO: over at www.Prevoman.com

http://www.prevoman.com/Pages/Air%20Bag%20Replacement/Airbagpg1.html

http://www.prevoman.com/Pages/Air%20Bag%20Replacement/IMG_3288.jpg

Now head over to Jon's post on trade-a-part and pickup a couple of free used ones to try out this HOW TO:

http://www.prevostownersgroup.com/forum/showthread.php?t=629

[truk4u]

Nice job Mango Man and you did it the hard way (no pit or lift)!;)

[Joe Cannarozzi]

Mike, That fitting on top of the front bag is a real stinker. We had an air leak there and you cant get a full bite on it, I was able to turn it MABYE 1/16 of a turn each bite.

The location of this fitting is a prime candadate for the new style compression fittings that are available. These do not use a compression ring or a threaded collar. You just push in the air line and its done. To remove the air line, its like a chinese finger lock, you simply depress the collar on the fitting and pull out the air line. The only other thing that could be an issue here is to make sure the air line is long enough to still make it to the new fitting after cutting an inch or so off the end of it to eliminate the old brass compression ring. Here is a picture. I didnt have a 90 to display but it will be the same as the T that is shown. Once you work with this new style you will hate the old!

544
old style, strait
545
new style T

I know that they are also using these new style fittings for water supply when plastic is used.

[MangoMike]

Tom Truk,

Real men don't need no stinkin' Pit. ;)

MM

[Jon Wehrenberg]

Mango has a little more to learn. He will be crying like a girl when he tries the rears and has to crawl under the rear end to access the fittings on the rear drive axle air bag on the Church of Love pavement.

I am taking photos and will be sending this stuff to Mango to add to his procedure. Joe is correct about the front air fittings being an issue, and especially the passenger side. We did my front bags exactly the way the factory built it by using a 13/16 box wrench and cutting an opening for the tube (like on a flare nut wrench). By using that wrench (flipping it) along with a standard open end wrench and a lot of patience you can make enough movement of the compression nut to eventually loosen or tighten it without cutting a groove in the foam I will supply photos of this for Mike to include also.

On Roger's coach however we decided against wasting so much time working the two nuts about 1/32 turn at a time, and we cut the air line at the compression nut, got a 1/2" street ell (brass), a 4" X 1/2" nipple, a 1/2" connector and a 1/2" tube compression fitting X 1/2" male fitting. This combination brings the compression nut beyond the top air spring mounting plate. Roger is working on some better photos than the camera phone one we have.

Mike will not believe this after what he went through, but I'm confident he could replace a front air bag after the wheel is removed and the old one is out in 15 minutes or less. A pit helps, but you can slide in there for the tag axle air fitting.

We are documenting the replacement of the rears (we replaced all four in my coach (not the forward drive axle, but the rear drive axle and the tag) in two hours, start to finish. The forward drive axle air bag will be more involved.

[Joe Cannarozzi]

Does anybody know how many hours labor a prevost shop says it would take?

Ill bet its at least double that!

Heck, they couldnt get the windows washed in that time.

[Jon Wehrenberg]

Joe,

Roger was quoted the time and cost. He agreed it was cheaper to give me his BMW M3 than to take it in to have the work done. So by helping him (he helped me also) I was allowed to actually look at the car.

I hope he posts exactly what and how he was told since I would only be passing the information along second hand. It was substantial, but if there was a breakdown in communications and is less than the amount quoted with our simple modifications we get the job done quickly.

I can tell you that we actually started on mine between 10:30 and 11:00 AM. We had to jack it up, put safety jacks under it, remove the tires, etc. We took 30 to 45 minutes for lunch, and by 4:00 PM we had replaced my fronts, and the rear drive and tag axle air bags. I did not replace the wheels on the rear because I am mounting new tires on them.

[MangoMike]

Whatever times Jon is posting for work performed should be taken with a grain of salt. I've seen him at work in the Pit and he's been professionally trained by NASCAR. Add to that he just wanted to get Fast Roger out of town, quickly and you have record speeds.

Great idea about cutting the wrench. That's the kind of creative thinking we need. I was also tempted to cut the air hose to make removal easier, but was too scared that I wouldn't find the correct parts to re assemble and get stuck in M. Beach. Am anxiously awaiting your photos.

Also very curious to see Fast Rogers post on his estimate from Prevo for the work, it will ease my girly tears.

As a side note just talked with JDUB in Libya where he's holed up in Libya's equivilant of the Bates Motel. Since the closest thing he has to the internet is a carrier pigeon now would be a good time to fire a couple of shots across his bow.

MM

[Jon Wehrenberg]

Taking shots at JDUB when he can't respond is no fun. But when he comes back and starts in again with his "hog can't tell time" stories we can jump on his sand filled butt.

Mike, I'm waiting for Roger to get some better photos, and I will summarize a lot of additional things, including some of the rear bag replacement process. Also, Roger and I have our forward drive axle bags to replace and we need to document that also so we will be feeding stuff to you as we can. I think the entire process can then be blended into the excellent one you did so it becomes a total How-To for air bags. It is with reluctance I offer the front air bag fitting modifications because a small voice says Prevost wouldn't fight with the front fittings like that on the thousands of coaches they have probably repaired....or would they? I would like to see the instructions include both ways and let the owner decide. If I were to have Prevost change the fronts however I would hand the mechanic the parts to do it the way we did Roger's and tell him that is how he will do it, and I will time him. It makes that big a difference unless they have developed a special tool just for the application, in which case the hours quoted to Roger were out of line.

Thanks for the NASCAR compliment, but we were not hustling. We just took an organized approach, but without Roger's help I would have been in and out of the pit (rears only) chasing parts and tools and that eats up time. Roger spared me that effort and it is a huge contribution to efficiency. Also, he is a good wrench, and if he wasn't selling them I almost believe he would be fixing them.

[Jon Wehrenberg]

Taking shots at JDUB when he can't respond is no fun. But when he comes back and starts in again with his "hog can't tell time" stories we can jump on his sand filled butt.

Mike, I'm waiting for Roger to get some better photos, and I will summarize a lot of additional things, including some of the rear bag replacement process. Also, Roger and I have our forward drive axle bags to replace and we need to document that also so we will be feeding stuff to you as we can. I think the entire process can then be blended into the excellent one you did so it becomes a total How-To for air bags. It is with reluctance I offer the front air bag fitting modifications because a small voice says Prevost wouldn't fight with the front fittings like that on the thousands of coaches they have probably repaired....or would they? I would like to see the instructions include both ways and let the owner decide. If I were to have Prevost change the fronts however I would hand the mechanic the parts to do it the way we did Roger's and tell him that is how he will do it, and I will time him. It makes that big a difference unless they have developed a special tool just for the application, in which case the hours quoted to Roger were out of line.

Thanks for the NASCAR compliment, but we were not hustling. We just took an organized approach, but without Roger's help I would have been in and out of the pit (rears only) chasing parts and tools and that eats up time. Roger spared me that effort and it is a huge contribution to efficiency. Also, he is a good wrench, and if he wasn't selling them I almost believe he would be fixing them.

[MangoMike]

Jon,

I'm very curious to see you and Roger's HOW TO: on the rears. I know when it comes time it will probably save me a lot of time and guess work. When you're done will make a first class webpage on the whole process. Something I don't think anyone has done outside of Prevo.

I'm with you as to the tried and true technique Prevo uses to remove that fitting or is it just like my legal team - the more billable hours the better.

Mike

[Jon Wehrenberg]

The rears (not including the front drive axle) are so easy it boggles the mind.

I will send the stuff this afternoon after I spread part of a semi load of mulch now blocking the end of my driveway, but except for a universal joint required for the inside bottom 3/4" nut on the tag axle those 4 air bags do not even require any explanation. You do have to get at the air fittings from the inside.

[Jerry Winchester]

Thanks Mike for that open promotion of defenseless hammering. We'll send some Ninja mechanics over to the Church of Love to review your work.

But on the brighter side, I made it out of hotel hell, so if Continental does their job, I'll be home shortly.

However, I have made a few interesting observations whilst here in the Netherlands.

First, there must be a tomato shortage here in Europe. Everyone charges for catsup like it was liquid gold. I'll need to carry some back over here for resale next trip.

On the trip over Continental lets you carry a bag onto the flight. Then no EU airline will let you continue with it, so you have to check it. I asked the BA chick if she would go ahead and file the lost luggage report. She didn't think it was funny and said they had a new company handling the bag transfer. I told her it didn't matter. My bag would never make it to Algiers and she should know that up front. I told her that living on a miserable island with shitty food and people with bad teeth didn't make it okay to pass that misery on to the rest of the planet.

Yes, my bags remained in London whilst I was in Algeria going commando with the underwear. I just threw them away after the third day.

Anyway, I have made my last flight on British Airways. You can carry an atomic reactor onboard Air Algerie, so flying the same airline the terrorists use has to be safer and a whole lot less hassle eh?

[Jerry Winchester]

Oh, and Jon forgot to mention that it only took him and Roger 15 minutes to eat. They spent the other 30 minutes bulking up with bananas so they could get their lunch packed. It must be hell to get old and irregular.

And your sand is in the mail...........

[Jon Wehrenberg]

Roger.....heeee's baaaack!

Here I am Mr. Nice Guy not taking shots while size 63 is pooping in the sand, and the first thing he does upon access to an electric source is take shots, not only at me, but you.

He seems to need a little slappin around.

[rfoster]

JDUB: So what did you have good to eat in Algiers? Bananas? Dates? Chocolate covered sand loaded Goat Turds? Camel Balls? any lamb fries? No BBQ joints on the side of the camel Path?

Yea Jon and I had a banana, because we wanted to. It is really tough to get "regular" flying around the world in those commerical Jets with the tiny crappers in the back. Your body doesn't know where you crapped last, but you buddy below wished you had - lighten his load. Glad to see you back, my hog has been watching the clock!
548

[MangoMike]

A1 Jon and Fast Roger show you HOW TO: replace the rear air bags.

http://www.prevoman.com/Pages/Air%20Bag%20Replacement/joncover_2702.jpg

View it here:

http://www.prevoman.com/Pages/Air%20Bag%20Replacement/Airbagpg5.html

mm

[JIM CHALOUPKA]

Jon,
In your directions for front air bag replacement, you added the fitting and pipe nipple at the inlet to facilitate reassembly. You indicated to cut the blue plastic tubing to the desired length apply the nut and ferrule and assemble.
This would necessitate the use of a new ferrule.
My question is;
Is the blue plastic tubing the same size as copper tubing thereby allowing a ferrule for copper to be used?
What is the proper terminology for the tubing used in the air suspension?
Where can the tubing and its appropriate fittings be purchased if they are not ordinary?

[Jon Wehrenberg]

Jim,

The modifications Mike showed are on the front air bags. If you review Mike's procedure you will see he had a hard time accessing and then removing and replacing the front air bag air supply fittings. Even by modifying a tool as pictured, the front air bag fittings are extremely time consuming to remove and replace as assembled by the factory. The modifications are suggested as a possble solution.

The fitting was purchased at Truck Pro, and all we asked for was a 1/2" tube to 1/2" pipe (male as shown). I do not know it for a fact but I presume the same would work for copper. We bought an entire new fitting because the one removed is a 90 degree and that would not work as we modified it.