air bags

[paultracy3]

i changed the right front air bag on my 99 newell . due to some cracks in the bag and was leaking down fast . right away i noticed that the travel ride hight was higher on that new bag , and the ride was much better . im thinking about putting all new bags on the coach . my bus mechanic says that all the bags have some dry rotting , just because of the age of the bags and the hot dry weather in the summer in vegas . my question is can a airbag lose its springweight as they get older ?

[Richard and Rhonda]

Theoretically it could loose a little spring rate. If the bag diameter grows as the rubber loses it's elasticity then it essentially becomes a larger diAmeter bag which would soften it's spring rate. More likely that the leaking bag caused the ride height valve to call for more air to keep the front end up. The end result is the leaking bag was softer than design and it's mate was harder than design

[larryweikart]

I believe Pauls Coach weighs quite a bit more than mine, but I have been thinking about replacing all of mine just because of age. Does anyone have an idea of the cost for having this done?

[paultracy3]

i depends wich way you go , i got the right front bag from newell and it was 350$ . now that i have the make and part # of the bag i can get the same bag from kenworth in vegas for 150$ . the rear bags are about 125$ per bag . then you have the labor to change them

[paultracy3]

she is up and bags are coming out.

[larryweikart]

Thanks for the info Paul. Let us know how much difference you think the new bags make.

[paultracy3]

i went by and 2 of the rear bags were out and had cracks that were leaking air . it has ti be better right ???

[encantotom]

i am sure it will be. what is interesting to me is that my coach is 9 years older and doesnt really leak at the airbags. and i am not going to just change them to be preventative.

i watched my bus shop change an airbag on a prevost in 15 minutes.

let us know how it works out

tom

[paultracy3]

my bus has been stored most of the time in lake havasu az , 120* summer temps and dry . im told the bags have dry rotting

[tuga]

I had an air bag blow out! We were at a POG (Prevost Owners Group) rally in Titusville, FL. Just sitting around shooting the breeze and BAM my driver's side rear airbag blew. Thankfully, there was an RV shop across the street and I had 2 spare air bags.

When an air bag blows, you are dead in the water. You're not going anywhere until that baby is changed out. If it blows when you are driving down the interstate you've got a big problem. Depending on where the bag that blows is located, towing the coach may not be an option; rear bag blows and I don't think you could tow the coach. If it is on the driver's side that means that the mechanic or you would have to work with interstate traffic whizzing by! Not good.

For this reason I have ordered all new air bags for my coach. The air bag rubber cracks just like tires do. If tires have a useful life then it seems logical that air bags would have the same.

Now I know what most of you are thinking: my coach is 20 years old and the air bags are still holding air. That may be true but personally I would rather do some preventive maintenance in a mechanic's shop than have to do it on the side of the road!

[encantotom]

tuga, i can't fault your logic at all.

my dilemma and a chunk of the people here, is how much do you spend on preventative work.

it is something i will have to think about more.

what i wonder is how many different airbags did newell use? do we share common part numbers or is it that you have to have one changed before you know what one you really have?

if i knew exactly what airbag i had, i could begin a shopping quest to get the cheaperst deal i could on them and be ready and or do it then.

ah.....the decisions.

tom

[GORDON HUMMEL]

different info

[tuga]

Tom,

You are correct about finding the correct air bag. When I called Newell and ordered spare air bags (this was before my air bag blew out) the ones that they sent me were the wrong ones! I only discovered this when the mechanic in Titusville tried to change the air bag that blew out! Newell over nighted the correct air bags to me (I decided to order 2) and we were back in business.

Since the air bags that are on the coach are old, it is difficult to read the numbers on the bag. So it then becomes necessary to remove the old bag, measure it, call in the measurements to Newell or whoever and wait for the new bags to arrive.

You can start to see why you would want to do this while your coach is parked at home or safely in Newell's service bay and not on the side of the interstate.

I know that none of us want to spend money that we don't have to spend, but I think that this air bag maintenance is worth every penny.

BTW, Newell Service DOES NOT RECOMMEND changing air bags at any certain interval. They have their agenda and I have mine. My air bags are going to be changed every 10 years! It is of course, up to the individual.

[Richard and Rhonda]

Just wanted to throw in my .02 with a warning. The air bags should be sized for the weight they are carrying. It's pretty simple math. If you take the diameter of the bag and convert to square inches and then multiply that by the air pressure in psi you have the carrying capacity of the bag. For example a 6 inch diameter bag would be about 28.3 square inches in surface area. So if you multiply 28.3 times 90 psi that bag would support 2545 pounds.

I walked through that to make this point. It very well could be that different length coaches were speced with different air bags. It could be a bad assumption to take part numbers from one length coach and assume they are the proper bags for another length coach. Slides and no slides would also call for different bags.

The air bag diameter can have a huge impact on how the coach handles. Let's take the example above. If we decrease the air bag to 5.5 inches in diameter, it would take 107 psi to support the same weight. If we increase the bag to 6.5 inches in diameter, it would take 77 psi to support the same weight.

What this means is the spring rate gets much stiffer as the air bag diameter decreases. Remember we do not control the pressure in the air bags, the ride height valve adds or lets out air until the coach reaches the set height. Of course if the air bag is really too small the valve can't apply more pressure than is in the air line to lift the coach.

Bottom line smaller bags equal stiffer ride, bigger bags softer ride.

Sorry to get all geeky on you, but I didn't want someone to post air bag numbers, and someone else to stock up on perhaps the wrong air bag.

Of course Paul knows about a million times as much as I about spring rates, so I'll shut up now.

[encantotom]

this whole discussion had me thinking....

so i called newell this morning and talked to chuck in parts. he said that since the suspension package all came in as one item from the mfgr, that they didnt keep track of what airbags were on each coach.

and that the only part number they pay attention to is the one on the top mounting plate that is covered when the air bag is installed. so the only way to accurately get the right one is to take one out for both front and rear axle since they were both different.

so, anyone wanna come over and take one of mine out so i can get the part number?

tom

[chockwald]

Richard, instead of becoming a rainmaker you could have a new career as a "technical writer"......

[Ron Skeen]

I have replace all air bags on drive and steer to Firestone WO1 358 9447. Newell had replace 1 bag on drive 4 yrs ago and 1 bag on steer 5 months ago and use Goodyear
1R11 066. I have 5 F/S which are 15 yrs old that anyone can have if you want to carry a spare. I also replace all 3 leveling control valves and anyone welcome to 2 of these ridewell valves. Have a great Day!

[jwe648]

I replaced all four rear airbags P/N: WO1-358-692 and all four torque arm bushings P/N: 23757 and had the rear axle aligned.. I feel better about the long trip now. One of the bags cover was spit bigtime. Interesting setup all mechanical runing off a seperate air tank. The shop in Gilbert did a good job and were reasonable $$. They found a few loose bolts in the front end and sinched them down... Drives Great...

[James Tuckness]

Has anyone changed out their own bags. Looks like a couple of 20 ton jacks would be all that you would need.

James Tuckness
71 30' 6 years on restoration, looking good now.

[Ron Skeen]

I changes all bags on steer and drive axle but not the tag. I also change 3 ride height valves. The job was done with 20T jacks and a couple of smaller jack to hold the alxes. I purchase all 8 bags for albout 1200 and pay a guy 160 to help. We spent about a day and the hardest thing was disconecting the air lines. My coach is 96 and had about 175K miles. I did remove the wheels which made it much easier to access the bags and valves. Good Luck and be Safe!

[gaz]

hi gaz in australia here,we have been on the road for 6 weeks,and have got a leaking air bag on the front does anyone know the part number and or were i can get replacmemt bag i will renew the four of them

my newell is a 1980 38ft 6v92 non turbo

thanks gary and suzie

[jwe648]

You will most likley need to pull a bag to find the p/n as it is on the end cap between the two mounting bolts. With that you should be able to google one up.. Try this site for starters when you get the P/N
http://www.truckspring.com/suspension-parts/firestone-air-bags.aspx

Be sure you crib the coach sooo you don't get stuck downunder in the down under...:)

Jimmy

hi gaz in australia here,we have been on the road for 6 weeks,and have got a leaking air bag on the front does anyone know the part number and or were i can get replacmemt bag i will renew the four of them

my newell is a 1980 38ft 6v92 non turbo

thanks gary and suzie

[James Tuckness]

I found the best price on bags at Stengel Bros. Inc., sales@stengelbros.com. 2b9-201 bags for $113.19 each. About $25 less than the best other price I found. Shipping in USA 3 day UPS $22.16. The 2b stands for 2 bellows, 9" dia. 201 is carry capacity. Local heave truck shop says 2-3 years life span for bags on heavy truck/dump truck apps. Coach life will be longer. I was given estimate of $1,300 for change out of 4 bags. The newest bag on my coach is a 1990 change-out. The rest may be original? 39 years old. Guess I got about all I can out of them. Let you know how the change out goes.

James Tuckness
71 30' work in progress.

[Bill & Sonja]

Just a shot in the dark, as I realize I'll likely have to pull a bag for the number. But does anyone happen to have a part number for an 87 tag axle air bag. Mine are Firestone. Bill

[jwe648]

This link show ways to identify the bag ...
http://www.truckspring.com/suspension-parts/firestone-air-bags/identification-tips.aspx

Hope it helps...

Just a shot in the dark, as I realize I'll likely have to pull a bag for the number. But does anyone happen to have a part number for an 87 tag axle air bag. Mine are Firestone. Bill

[Bill & Sonja]

The tag axle bag on our 87 is "Airide Springs by Firestone" , number on the air bag (rubber) appears to be - AY IT 15L ( what was previously noted as a "S" appears to be a backwards "2") F - near as I can tell. There are not any numbers on the top of the bag plate. There are two numbers under the bottom bag hardware. PN NBD 9661 and on a separate line - IT 15T 3 -

This bag has two studs to secure it on the top plate and one on the bottom centre. A large air hose enters on the edge between the two top studs on the tire side.

Newell is sending me a Goodyear Bag of the same configuration. I will post those numbers when I get it.

I have edited due to errors in reading the numbers prior to extensive cleaning.

--------------------- added info

New GoodYear air bag has been received from Newell and installed. Price from Newell was very reasonable and service was great. UPS delivery to Canada is another story, slow and very high brokerage fees over and above deliver and tax costs.

Newell's description of the bag on the invoice is - BAG AIR R/W 1003589447C STEER
the paper tag attached to the bag reads - 1R11-066
imprinted in the rubber - 566-22-3-021
on the bottom plate - 6 203 and AS3-20-7-055
I'm not sure what all these numbers mean but they must have some significance.

[gaz]

hi if you go to the truck spring site and put the last four digits from your piston (lower plate) in search box yours is 15L-3 that will give a range of bags to compare sizes ,when you get the right one go to stengal bros site and cross reference the number,this it what i did last friday and they shipped them to me in aussie should get them this week good luck

thanks for the info on the forum

gary susie



1980 38 ft and vitara toad

[James Tuckness]

Update on change-out of air bags on 71 30' coach. One person working it took 24 hours to do all work necessary. Hard work I will say. Just part of why restoration of one of these older coaches takes so long. You have to love it or you would never do it.

James Tuckness
71 30' 7 years in process. Glad it's down to maintenance work now.

[afrench45]

Does anyone know how much Newell charges to change a bag? My right front must be leaking because it is not holding air. Or could be a valve. Thinking going to Newell might be the easiest to solve the problem

[larryweikart]

Don't know where you live, but a good Truck Center can save you time and dollars My guys,Stoops, can fix most chassis items on my 94. Good Luck.

[RussWhite]

First thing anyone will want to do is find the leak. As you say it could be the bag, or valve, or even fittings or hose.

I bit the bullet and purchased an ultrasonic leak detctor because I do not like spraying watery mixtures around and watched them drip on me.

Check is out if you have time:

711-202-G1 Inficon Whisper Ultrasonic Leak Detector


It beeps when there is a leak and it even has headphones too. It should be able to find the leak quickly for you and then you can decide how you want to proceed from there. The seats on the solenoid valves are know to harden and leak. Good luck. Russ

[encantotom]

airbags are a very common item. going all the way to newell for that is kinda goofy in my eyes.

i use a local charter bus company that has a huge maintainence and repair shop and have gotten to be friends with the service manager. he works on private busses as a way to fill his guys time.

i was there one time and watched them change a rear airbag on a prevost in about 15 minutes.

within ten miles of my house are two places that would change an airbag easily.

so i agree with the others, find a bus repair facility or truck suspension repair place or other shop and i am sure then can do it easily.

tom

[leobess]

Hi, I have a problem with my air suspension, my coach is a 84 model. I had all new solenoids replaced and also new air bags. The problem is this, when I start the engine and get the correct air pressure, it wont airup in the travel mode.if I flip the switch to the level mode it will air up.by not airing in the travel I mean the front and the rear does not work.Is there some kind of fuse,or switch that has to be resetI'm at a loss as what to do next. any help any one of you could give, I wood really appreciate it. thanks in advance Leobess

[GORDON HUMMEL]

I suspect that when the solonoids were replaced, they were not wired back correctly. I'm assuming you have the same 6 pack solonoids as the later models. Looking at my 6 pack, the travel solonoids are on the right. down on the left; up in the middle. Get a test light & go back to the solonoids & with the engine running, you should have power to the travel solonoids. If you have power & they are working, then you have a plumbing problem with the air lines.
In as much as you can level manually, I suspect the plumbing is ok. Might want to have someone operate the up & down switches while you check out power to the solonoids with a test light.
On my coach, the power to activate the travel solonoids comes of a solonoid that I think goes to the transmission.

If the above does not help, a close up picture of the rear 6 pack would helpful

[afrench45]

I'm not familiar with the leveling with the vintage on your coach, but mine has a leveling override switch. If your coach has that, I wonder if there is something wrong with that preventing it from going into travel mode.

[rheavn]

Tom,
Where is the leveling override switch located on your coach? Hope mine has one.

[encantotom]

the leveling override on mine i believe is on the center console dash.

signed....the other tom

[afrench45]

Yea mines in the dash by all the other switches. Top left. I use it to raise my coach and back into my driveway.

[prairieschooner]

does your control panel have a Red Light that comes on when you switch the toggle switch to the Level Mode? there would be a separate toggle for each front solenoid (2) and each rear solenoid (2)

[leobess]

thanks for all the info, I sure could use it. I think I forgot to mention that everthing works great. I took a trip out west and went to Fla. and had no problems. One day I came back from a short trip, and parked the coach. Two days later I wanted to start it up, and it would not air up in the travel mode.Again I wood like to thank all you guys for the info, I dont know what I wood do with out you. Leobess

[HoosierDaddy]

leobess,
I'm not familiar with your system but I'd start at the travel solenoids . Use a test light to determine if they are getting 12V. They should magnetically attract a screwdriver etc if they are energized. If you have a "brainbox" for your leveling system check inside it for fuses. There may be a solenoid in the system that supplies higher amperage 12V to your solenoids. Also check the dash switch with a test light.

[leobess]

well I'm back, I went out and checked a few items. and had no luck.On my dash I have a switch that moves it from the travel mode to the leveling mode, when the coach is in the level mode a light comes on, to let me know its in the leveling mode.I'm going to let this thing rest till after chrismas. its getting a little cold outside to work. at least its cold in annapolis, md.I'll keep you guys informed. again thanks for everthing merry christmas leobess

[leobess]

well I'm back and I've got it fixed, I messed with it till i could not go any farther.So I took it to a place where they work on busses.At first, they repaced a leveling rod valve for the right rear wheel,also a valve for the brake pedal,because it leaked air.After the repaire on the brake pedal, it worked, But getting back to the right rear wheel, it still did'nt air up, so the man started to work on the solenoids, and found two of them had a bad ground, he cleaned them up and stared the engine, BINGO it worked. This is after a lot of greenbacks were paid.So from here on in if it doe'nt work check the ground first Again I would like to thank you for all the information. Please overlook the way I write because I dont know any better Leobess