Airbags, dry-rot

[david brady]

As other's have pointed out, there does appear to be an inner liner

built into today's air springs. I copied this following from
Firestone's

"Airide Design Guide":



"An air spring is a carefully designed rubber and fabric flexible
member

which contains a column of compressed air. The flexible member itself

does not provide force or support load; these functions are performed

by the column of air. Firestone air springs are highly engineered
elastomeric

flexible members with specifically designed metal end closures. The

standard two-ply version is made up of four layers:



(1) Inner Liner. An inner liner of calendered rubber.

(2) Frst Ply. One ply of fabric reinforced rubber with the cords

at a specific bias angle.

(3) Second Ply. A second ply of fabric reinforced rubber with the same
bias

angle laid opposite that of the first ply.

(4) Outer Cover. An outer cover of calendered rubber."



David Brady

'02 LXi, NC





Pete Masterson wrote:

I note that I've twice had competent service providers "carefully
inspect" the condition of my coach, and neither have indicated any
concern about the air bags. They don't look horrible, but do have some
checking and cracks on the outside. I take it that it's normal for the
age of the bags.

While I have no way of knowing (I'm at least the 3rd owner of
this coach), I doubt that any of the POs had the air bags replaced. The
immediate PO never mentioned air bags, and the (incomplete) set of
receipts he provided don't mention them either.

Pete Masterson

'95 Blue Bird Wanderlodge WBDA 42 (For Sale)

<http://www.aeonix.biz/BBforsale.html>

El Sobrante CA

"aeonix1@mac.com"

On Feb 28, 2009, at 10:57 AM, Wayne Kotila wrote:

David, I have a 1985 PT40 that I have owned for 12 years and
the air bags have looked that way as long as I have owned it. When I
bought the coach 12 years ago it had about 100,000 miles on it, now it
has about 160,000. I am not shure but I wonder if the bags have a thick
outer protective layer that we see cracking on the outside and the
actual bag sealing the air is a thinner moreplyable rubber on the
inside?

Wayne

---

From:david brady <"dmb993@earthlink.net">

To:"WanderlodgeForum@yahoogroups.com"

Sent:Friday, February 27, 2009
11:37:06 AM

Subject:[WanderlodgeForum] Airbags,
dry-rot

I was inspecting the coach the other day and noticed

that all my airbags are checked and cracked, similar

to the appearance of a dry-rotted tire. The bags are

7.5 years old. Anyone have a feel for how long bags

should last, and how severely checked they can become

before replacement is necessary? I have visions of

installing new bags only to find the same checkng one

year from now.



(Planning a cross country trip and want to be prepared).



David Brady

'02 LXi, NC

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