Front air bags on 81 280

[silverback]

The 280 is finally home after extended Chevy and Airstream dealer visits and it's amazing what you'll find when you have more time to check out (and clean) your coach. I was well aware we had rear air bag suspension. We just had it repaired (not sure it ever really worked ). Anyway I was crawling around looking at leaks (more on those in another thread) and noticed blue air bags in the front coil springs. Amazing I had missed that as I had crawled around under the coach before and was looking at the shocks yesterday. These have a valve on the bottom and do not look to be connected to the rear air bag compressor. I will research more, but are these stock on an 81 280 Excella? Any idea what pressure they should be set to?

Thanks,
Ken

[Mike Leary]

You can get a kit from most RV places to air the front bags from the engine compartment. I had front bags when we bought the coach, but when I had my front coils replaced, the techs advised me to throw them away, which I did and did not notice any difference in tracking or ride. The big deal is to have the coach aligned every few years. A Peterbuilt or such shop can get you within a few inches of plumb. That makes a huge difference concerning tire wear.

[345bill]

On our 345 the front bags require 55psi., no more- no less.

[Inland RV Center, In]

Originally Posted by silverback

The 280 is finally home after extended Chevy and Airstream dealer visits and it's amazing what you'll find when you have more time to check out (and clean) your coach. I was well aware we had rear air bag suspension. We just had it repaired (not sure it ever really worked ). Anyway I was crawling around looking at leaks (more on those in another thread) and noticed blue air bags in the front coil springs. Amazing I had missed that as I had crawled around under the coach before and was looking at the shocks yesterday. These have a valve on the bottom and do not look to be connected to the rear air bag compressor. I will research more, but are these stock on an 81 280 Excella? Any idea what pressure they should be set to?

Thanks,
Ken

The front air bags were standard on all Airstream motorhomes.

They were never connected to the rear air bag system.

They "MUST" be aired to 55 PSI, "ONLY".

Removing them permanently, is not something to even be considered, for "ANY" reason.

Andy

[John H.]

The aftermarket spring makers claim that the P30 chasis came with front coil springs to

" Light " to maintain the correct height, and stop constant bottoming out because of the total weight on the front axle !!! As I have seen so many say ! weigh the coach, weigh each axle !

Now after you weigh the front axle ! You can go to any good Truck spring shop and they can fix you up with the correct coil spring for YOUR Front axle and independent suspension system.

The Number 1 comment they ALL have made to me IS ! This front suspension was NEVER designed for this USE !!!

[Mike Leary]

Yup, I agree with John. My mechanic suggested the spring shop that services Fire Dept.
rigs, all overloaded in most cases. They did weigh the axles and measured the front to back, side to side. They said the P-30 chassis was prone to problems in the front end.
They installed heavier coils in the front and ripped the air suspension out and replaced it
with a type Kenworth and Peterbuilt use. The 60-40 switch came out and was replaced
with modern levelers. Problem solved after a few $$$$$$$.

[2airishuman]

this is a diesel moho?

did/do they have a different front end arrangement?

i dunno.

Originally Posted by silverback

....I will research more, but are these stock on an 81 280 Excella? Any idea what pressure they should be set to?...

one can certainly stick with the bag mod that a/s had to use for the p30 chassis.

these bags were common to many moho makes using the p30 which was UNDER sprung and needed help.

as john notes above the oem design was UNDER spec'd for this application.

many old threads here on this, including replacement (follow the LINKS inside) and great photos from old members.

http://www.airforums.com/forums/f159...ent-17305.html

http://www.airforums.com/forums/f159...eath-9121.html

but bags are just part of the equation, alignment and suspension bits may need help too...

more threads with GOOD LINKS inside...

http://www.airforums.com/forums/f311...ing-27175.html

http://www.airforums.com/forums/f160...ngs-35545.html

http://www.airforums.com/forums/f311...cks-39720.html

imo the UPgraded coils withOUT bags are a better approach and not that expensive as a useful modification.

UPgraded coils are a permanent fix and with no bags to inflate or fiddle with.

cheers
2air'

[Inland RV Center, In]

The air bags also provide a snubbing effect, springs cannot.

Andy

[2airishuman]

having driven a moho for 25 years...

half with the oem bag/coils and half without...

the bag/coils provide a sloppy, wallowing, vague driving experience.

like a 70s caddie.

imagine a small dip in the interstate that results in 4-5 bouncing undulations afterward.

that's the oem ride.

so IF you like that and like 2 MORE air valve to check before trips, then stick with the old stuff.

however AFTER proper modification with stiffer coils the handling becomes MUCH more precise.

not euro STIFF but firm and with a HUGE improvement in steering/lean/roll and control.

read the old threads and check with vendors.

swapping out these 70s/80s bag/coils was very very common.

cheers
2air'

[silverback]

First, all sway bar bushings are new. For now I will "carefully" fill the front air bags to 55 PSI. In the future I will find a truck shop in Phoenix (or Tucson) to align the front and install the P30 "Super Coils". Sounds like they may or may not include air suspension. Probably replace the Monroe shocks too. The coach does not appear to be out of alignment now (based on steering and tire wear) but I will get it checked. It does seem a bit "tippy" when cornering.

Thanks,
Ken

[silverback]

Mr. 2air is correct, adding air to those bags is a PIA. And my compressor was complaining about the very log extension cord I ran out to the curb. Anyhow both bags are now at 55 PSI. When I first checked, one was at 25 PSI and the other was near 40 PSI. Guess the good news is they both still hold air. Now we'll see if it actually makes a difference.