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andyleonard8 · 04-24-2025, 05:59 PM

I'm redoing the 454 TBI and have 18psi on the gauge at the carb assembly. Motor has had headwork, headers and a cam so a little extra fuel pressure can't hurt, but 18 seemed like a lot for a 9-13psi system. I'm aware the newer system uses up into the 30's, but this is the old style. Hmm.

Then I did something radical and actually read the Airstream Manual for 1991 and saw "18psi" as the recommended pressure.

I have yet to see anything on the web about an 18psi spring/setting on a 454 except on the 454SS hotrod forum where up to 22psi old-style can be used.

Who at Airstream decided to up the pressure to 18psi and when/why did they do it and why does no one at any parts house know about this?

Runs great by the way.

PeterH-350LE · 04-27-2025, 07:06 PM

Quote:

Originally Posted by andyleonard8

....

Runs great by the way.

Cant asked for more! Why Airstream did so many things on those classics is a big mystery and my suggestion is don't mess with it if it works!

andyleonard8 · 04-27-2025, 08:22 PM

Well, I don't know how they ended up with 18psi as a spec for a stock motor, but it sure looks like that's the sweet spot for my modified motor. 22 psi and it runs fine - at 10.5 AFR. 15 psi and it's uncomfortably lean at mid-14s to 15s AFR. I'm going to shim the 15# spring and try to hit high 12s to mid-13s AFR and I'll bet that'll turn out to be 18 psi.

On another note the mice got a wire on the furnace which I had to pull today. What a PITA. I'm ordering a heatstrip for the new Furrion AC unit, just in case.

PeterH-350LE · 05-02-2025, 04:59 AM

did you replace the Airbags on your 300? If so, do you know the parts number? Does your manual have a picture of your rear suspension?

andyleonard8 · 05-02-2025, 10:20 PM

If you mean *rear* airbags, yes I replaced them...but it was so long ago I have no clue where I got them. If you mean front airbags, no, mine were converted to springs when I got it.
I happen to have the wheels off right now for brakes and new tires, so if a pic of the rear suspension would be of interest, let me know. It's up on levelers so bags are in full droop and completely extended.
I'll check the manual for you tomorrow.

PeterH-350LE · 05-03-2025, 05:45 AM

Quote:

Originally Posted by andyleonard8

If you mean *rear* airbags, yes I replaced them...but it was so long ago I have no clue where I got them. If you mean front airbags, no, mine were converted to springs when I got it.
I happen to have the wheels off right now for brakes and new tires, so if a pic of the rear suspension would be of interest, let me know. It's up on levelers so bags are in full droop and completely extended.
I'll check the manual for you tomorrow.

Yes, rear airbags. I would like to see a picture. There is a number on the bags, can you possibly locate them?
thanks a bunch

andyleonard8 · 05-03-2025, 10:18 AM

Maybe there's number I can see when the rain stops.

andyleonard8 · 05-03-2025, 10:19 AM

Attached

PeterH-350LE · 05-03-2025, 12:57 PM

thanks, but thats the airbags system on all Classics Except the 1991/1992 300's
Did you replace the airbags, do you remember how you detached the bottom plate of the bag. Only way I can see doing it is be rotating the airbag?

PeterH-350LE · 05-03-2025, 02:41 PM

also curious why you dropped the airbag support beam to work on the brakes?

andyleonard8 · 05-03-2025, 04:45 PM

Those 3 pages are from the looseleaf factory manual that came with my 1992 300LE and is labelled as such. I *believe* there's a single nut up inside the bottom bag insert/plate. I also think the bottom plate stays with the rig and is not replaced when the bag is renewed. I didn't remove anything when I put it up on the levelers just now to remove the wheels. It does look like it's drooping a lot but I'll have to look. I pulled the wheels off in weather, threw them in the truck to take to the tire store and haven't remounted anything yet. When it dries out I'll go under and report back.

PeterH-350LE · 05-03-2025, 05:13 PM

Quote:

Originally Posted by andyleonard8

Those 3 pages are from the looseleaf factory manual that came with my 1992 300LE and is labelled as such. I *believe* there's a single nut up inside the bottom bag insert/plate. I also think the bottom plate stays with the rig and is not replaced when the bag is renewed. I didn't remove anything when I put it up on the levelers just now to remove the wheels. It does look like it's drooping a lot but I'll have to look. I pulled the wheels off in weather, threw them in the truck to take to the tire store and haven't remounted anything yet. When it dries out I'll go under and report back.

Thanks, yes it seems that all the 300 owners got the 350 manual. I no longer need the Air bag number, I am pretty certain its the W01-358-5412
Are you sure your safety harness is still connected to keep the airbag bar from dropping too far ?