Airbags

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Airbags

August 24, 2013, 12:30:48 pm

New to the forum and looking for answers. We have a 1989 Grand Villa that shortly will need all 8 airbags replaced. I am doing the research and hope that someone can help me in the right direction on where to buy these and if we can replace them ourselves.

Re: Airbags

Reply #1 – August 24, 2013, 01:40:04 pm

Pretty easy job if you are a little savy. No need to remove any body parts or even the tires. You do need some 1/2" extensions for a ratchet so you can just lie on a blanket and reach the bottom nuts. On the front bag backside, you will need a special crowsfoot like pictured in the post photos. I cut a box end wrench to fit the big nut on the top. Box would not clear the body without cutting it in half. The bags are about $57/each delivered with no tax. See an earlier post for more information. Air ride bag replacement number?

PM with any questions.

Pierce

Re: Airbags

Reply #2 – August 24, 2013, 04:31:14 pm

Just noticed I left the $1 off the amount. Here is the site I used at $157/each: http://www.truckspring.com/Products/Firestone-Reversible-Sleeve-Air-Spring__W01-358-9448.aspx

Pierce

Re: Airbags

Reply #3 – August 24, 2013, 04:34:24 pm

Pierce has the wider body coach and it probably is possible to change the airbags without removing any body panels on the wide body. You have the narrower body coach like mine. I just changed two of the rear airbags on my 1991 model and it wasn't possible to change the airbag in front of the rear axle without removing the fender. Removing the fender isn't a lot of extra work though. I still haven't changed any front airbags yet so I can't comment on how difficult those are. It took me about three hours to change the most difficult airbag, which is the one in front of the rear axle, and it was my first attempt with no prior experience. The airbag behind the rear axle was a lot easier and took a lot less time. The best price I could find for the airbags was at Truckspring.com and the model no. is W01-358-9448. The airbags are $155 each total cost with shipping and everything included. I intended to change all 8 airbags on my coach but I never had the money so I've been carrying a spare airbag and a stubby bottle jack with me at all times. I drove for over a year 15,000+ miles before the first airbag started leaking real bad. After it started leaking I managed to drive another 50 miles before I changed that airbag. I just replaced another leaking airbag last weekend. Both airbags looked really bad, with broken cords visible through the cracked rubber. None of my other airbags look as bad as those two did. Both airbags started leaking while I was sitting still in a campground, not while I was driving. This defies logic but that's the way it happened in my case. Don't worry too much about airbags. I did before but now that I've replaced a couple of them I don't think they're any big deal. Carry a spare airbag and a jack and wrenches and you'll be okay until you can get them all replaced. Call me if you need to and I'll talk you through it.

Scott
(615) 482-7650

Re: Airbags

Reply #4 – August 24, 2013, 06:32:16 pm

I have been replacing mine and have found this place very good. Leaf Springs, Helper Springs and Suspension Parts | SD Truck Springs

They have a coupon code you enter depending on your purchase amount, and free shipping, no tax.
The springs always have been here in 2 days after I placed a order.

Re: Airbags

Reply #5 – August 24, 2013, 09:02:16 pm

I had all 8 air bags replaced on mine shortly after purchase. Scott is correct, the rear front bags require flexing out or removing the fender panel on the narrow body coaches. Parliament Coach in Clearwater FL did mine, 2 techs worked for most of a day. I feel much better not having to worry about them.

Re: Airbags

Reply #6 – August 25, 2013, 11:18:31 am

Thanks for the info on where to get the air bags, I'm thinking that I should be looking at replacing ours on our 91 GV. What are You using for criteria on whether to replace them or not? Is some checking OK? Do you wait until they start leaking? I'm sure that someone has gone thru this and has a good base for evaluation. Have a great day ---- Fritz

Re: Airbags

Reply #7 – August 25, 2013, 03:30:31 pm

...check your wallet first, if that indicates that you can't change all 8 airbags you need to carry a spare airbag with you at all times ...that's the only criteria I checked

Re: Airbags

Reply #8 – August 25, 2013, 03:32:46 pm

Fritz, are you sure you have an airbag suspension? Which model coach do you have?

Re: Airbags

Reply #9 – August 25, 2013, 05:02:03 pm

Fritz,
When examining your airbags for wear, look closely at the upper curvature of each bag. Checking of the rubber is not the issue; rather, look for exposure of the cords embedded within the rubber. An occasional cord visible isn't a big deal. If several inches of cord are exposed, are any of the cords frayed? If so, the bag should be replaced. Beneath the cords is an additional 1/8" of rubber that will gradually fatigue (causing a leak), but the inner rubber doesn't check; it will show stress lines. As I recall, the airbag immediately in front of each tire (especially on the rear duals) will exhibit the most wear.

My air bags didn't leak, but extensive sections of cord were showing and the bags were 20 years old, so I bit the bullet on all 8 bags.

Re: Airbags

Reply #10 – August 25, 2013, 06:38:22 pm

My bags were original on my 95. They didn't look too bad, but then suddenly my right rear (front) bag sprang a leak. My air compressor was able to keep up long enough for me to get back home (about 20 miles. I didn't know the bag was blown, all I saw was my air gauge struggling to keep air pressure up. When I got home and inspected I found the blown bag ).
My mistake when inspecting was that I didn't raise the coach all the way up when I inspected. The worn rubber on the bag was partially hidden because at rest the bag folded over the "bad" part what showed didn't look that bad.

When I removed the bags I could see how worn they REALLY were. I vowed I would not go any place until ALL were replaced.

If a bag were to blow while you are away from home I wouldn't count on doing a road side repair.
I found that with a blown bag the other bag at the wheel will NOT be strong enough to lift the coach at that wheel. You cannot get to, or even reach a bag if the coach is resting on the tire. You will have to be able to jack up the upper frame member and lift the coach off the bag at least 7" in order to get the old bag out and new bag in. This is something you probably won't have the tools for on the side of the road. You will be forced to have the coach flat bed towed someplace. This will cost you far more than the cost of replacing all the bags. You will also be stuck waiting for a replacement bag and waiting for a installation bill from somebody that has NEVER replaced a bag on a Foretravel before let alone seen one, or even know what a Foretravel is, neither will there local parts guy.

Bite the bullet and replace them all, the peace of mind will be worth it.

Re: Airbags

Reply #11 – August 25, 2013, 09:57:12 pm

Lon,

You are right on about the other bag not being able to lift the coach especially in the back where all the weight is. I do carry a couple of extra bags along with the tools to change them. The jack I have is the same that I would use for my spare and the other tools are just the normal stuff I carry with the exception of the special crow's foot I made, the shortened box end wrench and a safety tool in case the jack collapses. These are all VERY small. Our extra air bag fits nicely into a empty white kitty litter container.

Since the leak is almost always where the tire throws up road debris and in plain sight, if you jack up the rig and then either force in JB Weld for a quick set or inject Silicone II and let it set overnight, you can then drive to a shop or home to get it replaced.

A leaking air bag can almost always be detected if you are watching the air pressure at all. It should be second nature how often the compressor cycles on and off. Any change in the frequency should be followed up by squirting a soap solution on the bags. Not hard to do and can save a lot of headaches. The bags are very thick and don't usually suddenly blow out but gradually develop a small leak that will grow if not paid attention to. I mean, how much work is it to occasionally squirt some soapy water on eight bags?

Maintenance on an RV should be a pro-active thing. Sure, there are sudden blow outs and alternator failures but it has been my experience that many failures give a warning well before they fail completely. If you don't check that alternator belt, you can't be too surprised when it breaks. Learning the symptoms before the failure occurs is an important tool in not only having a trouble free trip if that is possible but for you and your family's safety as well.

Pierce

Re: Airbags

Reply #12 – August 26, 2013, 08:47:59 am

Both of the airbags that have leaked on my coach so far have leaked near the bottom of the bag on the side away from the tire. I knew they were bad because I could feel the broken cord back there even though I couldn't see it. The bag behind the rear axle can be examined through the small door behind the rear wheel and I could see how bad that one was. I didn't have the money to change all 8 airbags so I carry a spare airbag with me at all times along with a stubby bottle jack that will fit in beside the airbag. I have a 36' coach that is lightly loaded and I was able to lift the coach with a leaking airbag after I drained the water tanks. I had to start the main engine because the electric air compressor didn't produce enough air to lift the coach with a leaking airbag. I'm told my coach is probably light enough to lift itself with one airbag if I drain the water tanks and plug the air line to the leaking airbag, but I didn't have to do this. I don't know if a 40' coach would be light enough to lift itself with one airbag. You only have to lift the coach a little bit just so you can get the stubby bottle jack in beside the airbag. Once you get the jack in there you can change the airbag. The shorter the jack is the easier this will be. Don't worry too much about these airbags. If you can change a tire you can definitely change an airbag. It's much easier than you think. I changed the radiator in a parking lot after every diesel mechanic in town refused to work on it because it was too difficult. I called Foretravel and they told me exactly what to do and it worked out just like they said it would. Changing an airbag isn't a difficult job and you can handle it. After you change one you won't be worried about airbags anymore.

Re: Airbags

Reply #13 – August 26, 2013, 10:44:36 pm

Our 91 GV is on an oshkosh chassis and it has air bag suspension. I have to crawl under it to see the air bags (which I have done), but I prefer (and will) take it to a local shop that has a drive over pit. The air sys. schematic that I have only shows 4 bags, so I need to get under there and count them. I know that I will feel much better getting all of them replaced, Just the over cautious person that I am. When I was 20 years younger, the "carry a spare and some tools " approach would sound OK to me. Thanks for the help ---- have a great day ---- Fritz

Re: Airbags

Reply #14 – August 26, 2013, 10:55:06 pm

Yes, an ORED will have four air bags mounted inboard. Less chance of UV light damage.

Re: Airbags

Reply #15 – August 27, 2013, 09:44:51 pm

Brett ---- Thanks for that info, the ones on my Ored are large, looks like about 12'' or so in dia. Are these larger than the coaches with 8 air bags. My 91 GV also has large leaf springs in addition to the air bags. Thanks again ---- Fritz

Re: Airbags

Reply #16 – August 27, 2013, 10:03:50 pm

Fritz,

You will want to contact Freightliner with your Oshkosh chassis number. They bought Oskhosh: Freightliner 800 385-4357

Re: Airbags

Reply #17 – September 04, 2013, 03:00:28 pm

More home work on air bags: In discussions with Freightliner and Foretravel, what I have learned is that the earlier coaches (mid 80s to early 90s) (not sure of exact years) will depend on the chassis as to whether or not you have an air bag suspension. The Oshkosh chassis with the 3208T Cat. engine has airbag suspension and the chassis with the cummins diesel had coil and leaf springs and no airbags. These coaches have the 4 airbag suspension. I don't know what chassis in these years had an 8 airbag suspension sys. If you need airbags for the Cat. diesel chassis, Freightliner can give you the part numbers for front and rear and order them for you. They will cost just under $200 apiece and It will take about 2 months to get them. You may also want to get the manufacturer and part number from the airbag itself because there is alot of ambiguity in this area and it will help you get the proper ones. I am going to inspect the ones on our coach, get any info that I can from the installed airbags and get a set ordered if needed. I would not recommend waiting for a failure before taking action. This does not appear to be a roadside repair operation. Thank you all for the input and info ---- Fritz

Re: Airbags

Reply #18 – September 04, 2013, 03:41:45 pm

Oshkosh chassis were either leaf spring front and rear or 4 air bag.

Foretravel U280 and U300 were 8 outboard air bag.

Re: Airbags

Reply #19 – September 04, 2013, 06:16:51 pm

I dont know what happened to my rig, but it is leaf spring with 4 air bags. The air bags are for air ride and do not have a leveling function. leveling is done with the HWH system hydraulic jacks. There is no adjustment of any kind on the air ride, you get whatever the sys. is set to deliver.
these older rigs seem to be a world unto themselves. Thanks and have a great day ---- Fritz

Re: Airbags

Reply #20 – September 05, 2013, 12:25:51 am

Quote from: fkjohns6083 – September 04, 2013, 06:16:51 pm

I dont know what happened to my rig, but it is leaf spring with 4 air bags. The air bags are for air ride and do not have a leveling function. leveling is done with the HWH system hydraulic jacks. There is no adjustment of any kind on the air ride, you get whatever the sys. is set to deliver.
these older rigs seem to be a world unto themselves. Thanks and have a great day ---- Fritz

You have full lenght leaf springs that terminate at both ends with a spring hanger?

Or a metal arm that ends at the axle where the air bag is located?

Trailing link suspension. Pivot point is in front of the axle?

Bob

Re: Airbags

Reply #21 – September 05, 2013, 08:02:12 am

Yup, as Bob said, you DO have the 4 air bag suspension. Though it appears to be a leaf spring, the rear-mounted air bag is what sets ride height.

Re: Airbags

Reply #22 – September 05, 2013, 10:41:13 am

Well, it looks a little different to me in that it does have what looks like a half of a leaf spring on the forward side of both front and rear. The air bag sits on top of the axle where the spring is attached. The front and rear are both attached about 3ft in front of the axle. Is there something that I am overlooking in the rear leveling dep't? It seems automatic to me. My big concern in knowing all of this is what happens if I lose an air bag when traveling down the road at highway speed? When I shut down, my air stays up well and the bags lose air slowly over time and the coach settles a little but not down on the tires. There is not a dumping of air to settle the coach. Seems like it should ride OK until I can get it to a repair station. What do you think?? Thanks and have a great day ---- Fritz

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