Air Bag Question

[jozee]

I have been reading all of the manuals and materials that came with my recently purchased '98 Class A Tiffin Allegro.  I stumbled across something in the previous (and I believe original) owners handwriting that states:

M/H tires 85 psi cold
Air Bags 65#

I get the 85 pound pressure recommended for the tires (when tested cold); but have no idea what the Air bag reference is.  I can't find any air bags (assuming that they would be in the dash), so I must believe that motor homes have some sort of other air bag.  There is no reference to air bags in in the Chevy Chassis owners manual that came with the rig, so I am stumped.

What is an Air Bag.  What does it need 65 of?  Thanks again for the help!

Jozee

 

[Jeff]

Jozee:

Check the front coil springs. If it is a GM chassis there are probably air bags inside the coils that can be aired with a regular air hose and gauge.

 

[jozee]

Thanks Jeff!
I am still learning, so I don't know what front coil springs are.  They are not in my owners manual either.  Can you tell me what and where they are?  I don't have a problem sliding under the rig, if need be.  Just let me know.

Jozee

 

[Karl]

Jozee,

If you look just inside each of the front wheels where they are mounted to the steering arms, etc., you will (may) see a large coil about 10" high, about 6-8" in diameter, and made from roughly 1/2 to 3/4" steel. These are the coil springs, and the air bags should be mounted inside of them. They're made of black rubber, and will probably fill the space between the turns of the springs. You will also find a valve attached to each one that is exactly like the air filler valves on your tires.

 

[jozee]

Karl, thanks for the info.  I can't wait to get under the rig and see for myself.  It sounds like coils are the same as "shocks" on cars, and air bags are some kind of assistance to the shock absorbers.  Is that right?  If so, why don't I have rear coils and rear air bags?  Or maybe I do.  I will check all wheels, if that is possible.
Am I getting this right?  Also, do I check air bag pressure as often as I check tire pressure (which is before every trip, big or small)?
Jozee

 

[Tom]

Jozee,

The reason for air bags on the front is to assist the springs (suspension) and allow the front axle to carry a heavier load. They're probably not required on the rear axle.

No, they're not like shocks. Take a look at this link to see what they look like. You'll have to skip some of the photos and much of the text because the link is for replacing the air bags when they've gone bad. But it should give you some idea of what they look like.

I found that the act of checking the pressure in the air bags actually lets some pressure out. So I had to start with higher pressure than required and check it a few times until it came down to what I needed. In my case, it was 50 lbs, but yours might well be 65 lbs.

 

[John From Detroit]

Air bags means two things.  In cars Air Bags refer to the bombs they factory install in the cars which blow up in your face if the car is dented..

But in trucks the term "Air Bags" is often used to mean Air Springs, these are not shocks (though there are devices called Air Shocks which include an air bag suppot system in the shock) or they can be seperate devices

Visit this URL http://www.truckspring.com/  and look for something like the top left "Sample" graphic (Air Spring Kits)

 

[jozee]

Ok, I think I get it now.  The information that everyone provided is very helpful, as are the links.  I will take a look this weekend to see if I can find the air bags and check the pressure.  The tip to overfill a little and let the air out to the appropriate pressure seems like a good idea.
Once again, Thanks!
Jozee

 

[Tom]

Jozee,

Valves for the air bags may be at the bottom, underneath the springs, or they could be at the end of air hoses run somewhere more convenient. Take a look under there and, if you see hoses attached to the valves, follow the hoses to see where they end up. The valves will be just like the valves on your tires.