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Air Bag Pressure

I was having some work done on my coach when I overheard the service manager tell another customer that he had lowered the airbag pressure on his coach to give him a softer, less jarring ride.  Have any of you heard of this?  Or had it done to your coach?


Larry

Re: Air Bag Pressure

Reply #1
Not sure about the coach he was talking about but if you lower the pressure the coach will sit lower.
96 U270 BUILD 4810
85 380SL
Drummonds TN.

Re: Air Bag Pressure

Reply #2
What year coach do you e?
previous 1984 35 ft ORED 250 HP 3208 Cat       
previous 1998 40 ft U295 CAI 325 hp Cummins
previous 2003 40 Ft u320 build #6140 450 Cummins M11.                                                         
1999 Mazda Miata
Ron, Nancy, Tipper the cat, Max The dog
1997 U 270 36 ft build number 5174 8.3 Cummins

Re: Air Bag Pressure

Reply #3
Not possible to lower air bag pressure on any air suspension coach I know of without lowering RIDE HEIGHT.  A dangerous solution-- hard on suspension and drive line!

Would love to know what coach and who in the world recommended this!
Brett Wolfe
EX: 1993 U240
Moderator, ForeForum 2001-
Moderator Diesel RV Club 2002-
Moderator, FMCA Forum 2009-2020
Chairman FMCA Technical Advisory Committee 2011-2020

Re: Air Bag Pressure

Reply #4
Maybe he was talking about tag axle air bag pressure, some coaches have an adjustable regulator, so you can load or unload the weight the tag bears.
Jim C.
coachfree, previous 1997, 1999, 2000, and 2003 Foretravels.

Re: Air Bag Pressure

Reply #5
Didn't ask the service manager because it would be somewhat embarrassing to admit I was eavesdropping on his phone conversation.

Re: Air Bag Pressure

Reply #6
Maybe he was talking about tag axle air bag pressure, some coaches have an adjustable regulator, so you can load or unload the weight the tag bears.

Could be, but changing tag axle pressure would have very little effect on ride quality and if lowered, would materially overload the drive axle and under-load the steer axle.
Brett Wolfe
EX: 1993 U240
Moderator, ForeForum 2001-
Moderator Diesel RV Club 2002-
Moderator, FMCA Forum 2009-2020
Chairman FMCA Technical Advisory Committee 2011-2020

Re: Air Bag Pressure

Reply #7
We have Firestone air bags on my Excursion front leaf springs,lowering pressure does lower the truck,could be what he heard.
96 U270 BUILD 4810
85 380SL
Drummonds TN.

Re: Air Bag Pressure

Reply #8
We have Firestone air bags on my Excursion front leaf springs,lowering pressure does lower the truck,could be what he heard.

Ya, AIR-OVER ________ is very different than air suspension!
Brett Wolfe
EX: 1993 U240
Moderator, ForeForum 2001-
Moderator Diesel RV Club 2002-
Moderator, FMCA Forum 2009-2020
Chairman FMCA Technical Advisory Committee 2011-2020

Re: Air Bag Pressure

Reply #9
Could be, but changing tag axle pressure would have very little effect on ride quality and if lowered, would materially overload the drive axle and under-load the steer axle.
But isn't it possible that if tag pressure was too high, weight would be transferred to the front axle, perhaps overloading it, and front bag pressures would increase causing a rough ride, and if too high, would also unload drive axle and perhaps overload tag axle causing a problem there too?
Jim C.
coachfree, previous 1997, 1999, 2000, and 2003 Foretravels.

Re: Air Bag Pressure

Reply #10
But isn't it possible that if tag pressure was too high, weight would be transferred to the front axle, perhaps overloading it, and front bag pressures would increase causing a rough ride, and if too high, would also unload drive axle and perhaps overload tag axle causing a problem there too?
Absolutely.

Incorrect tag PSI/load can either under or over load the other axles.

Ideal is to have the same percent of GAWR on each axle.

It really takes scales to properly set this-- been there, done that!
Brett Wolfe
EX: 1993 U240
Moderator, ForeForum 2001-
Moderator Diesel RV Club 2002-
Moderator, FMCA Forum 2009-2020
Chairman FMCA Technical Advisory Committee 2011-2020

 

Re: Air Bag Pressure

Reply #11
Surely the air pressure in the air bags is directly related to the weight supported by the air bags and the only way to adjust the ride height is by adjusting the ride height valves.
                                                                                                Cheers, Mike.
Shady Lady
98 U270  34'