Airbags, is 1/2" air Inlet ok verses 3/4" okay?

[Woody O]

I am in need of replacing my 10 airbags.  Josam's wants to replace bags with standard air inlet, I think is 1/2" inlet  verses the 3/4" size inlet that is currently on coach. Going with the smaller size air inlet, will it change the leaning of coach going around curves? To the people who have already changed out your airbags and went with the smaller size inlet, did you notice any difference when driving. My coach is 2006 Dynasty 42' with tag.

[Mark Holt]

I would get an opinion from Oregon Motor Coach or Premier in Oregon. They both have folks on staff that worked for Monaco and Country Coach when your chassis was built. I would think that the Monaco chassis had 3/4 inlets for a reason over 1/2". I had the unfortunate experience of having a Trucking Industry shop replace the bags on my coach and spent a lot of time and money getting the work corrected at OMC. Good Luck

[vito.a]

What happened to all your current air bags?  If not leaking, maybe wait until the parts shortages subside.  

The 3/4" air fittings on the air bags is reduced to 1/4" to fit the hoses, so I wouldn't worry about 1/2".  I would be concerned about the other aspects of the different part number airbag.    

My notes on air bags: Contitech AS8897 - Find it Parts $127 free shipping.  This bag has 3/4 NPT for air fitting. You might need 1/4 x 3/4 bushing, I did on some of mine. 

Here is a link to MJ's website showing the Contitech AS9376 which is the direct replacement for the Firestone W01-358-9376 use on many Monaco coaches from the early to mid-2000's.
https://www.truckandtrailer.parts/Co...02_p_1477.html

A link to Mike Z's post on replacing the airbags in his Dynasty.  This is a 105 page thread, so you'll need to search backwards until you locate the pages on airbag replacement.   https://www.irv2.com/forums/f115/mods-upgrades-to-our-2003-dynasty-237276-105.html

Edited February 10, 2022 by vito.a

[Paul A.]

Contact Jim at; http://sourcerv.com/. Experts on the Road Master Chassis.  Vito is correct.The AIR LINE is the determining factor for the volume of air going into the air bag.

[Ivylog]

There is a mod to reduce the leaning… restrictors in the airlines to the bags so not a problem and it’s probably a 1/4” line.

Edited February 10, 2022 by Ivylog

[Frank McElroy]

The larger diameter air lines are required on coaches with Ping tanks.  If your coach has these tanks, the larger lines will provide rapid air transfer between the airbags and the ping tanks.  In effect the air volume is much higher with these tanks vs just the airbag so you get more of a softer ride.  On my Dynasty I have two ping tanks on the steer axle, none on the drive axle.  The Signature and I think the Executive have ping tanks also on the drive axle.

[Mark Holt]

Frank is correct regarding ping tanks and air volume. It is just a personal opinion of mine but I would pay for the quality of a Firestone or Goodyear bag over the Chinese BlackTech. A blown airbag will stop you dead in the water on the side of the road just like a blown tire.

[Woody O]

On 2/10/2022 at 6:10 PM, Frank McElroy said:

The larger diameter air lines are required on coaches with Ping tanks.  If your coach has these tanks, the larger lines will provide rapid air transfer between the airbags and the ping tanks.  In effect the air volume is much higher with these tanks vs just the airbag so you get more of a softer ride.  On my Dynasty I have two ping tanks on the steer axle, none on the drive axle.  The Signature and I think the Executive have ping tanks also on the drive axle.

Frank, you have a Dynasty and I have a Dynasty. Do you know the size of the airlines going to your airbags on front? I thought they were 1/4", but I haven't looked lately.

[Frank McElroy]

The larger diameter air lines are required on coaches with Ping tanks.  If your coach has these tanks, the larger lines will provide rapid air transfer between the airbags and the ping tanks.  In effect the air volume is much higher with these tanks vs just the airbag so you get more of a softer ride.  On my Dynasty I have two ping tanks on the steer axle, none on the drive axle.  The Signature and I think the Executive have ping tanks also on the drive axle.

1 hour ago, Woody O said:

Frank, you have a Dynasty and I have a Dynasty. Do you know the size of the airlines going to your airbags on front? I thought they were 1/4", but I haven't looked lately.

The lines going to the ping tanks are 1/4" but the line coming out of the two ping tanks to the front steer axle airbags are much larger.  I didn't measure them but guessing about 3/4".

On my drive and tag axles, there are reducer fittings at the airbag to feed the 1/4" air lines.  I don't have ping tanks in the rear.

[Woody O]

2 hours ago, Frank McElroy said:

The larger diameter air lines are required on coaches with Ping tanks.  If your coach has these tanks, the larger lines will provide rapid air transfer between the airbags and the ping tanks.  In effect the air volume is much higher with these tanks vs just the airbag so you get more of a softer ride.  On my Dynasty I have two ping tanks on the steer axle, none on the drive axle.  The Signature and I think the Executive have ping tanks also on the drive axle.

The lines going to the ping tanks are 1/4" but the line coming out of the two ping tanks to the front steer axle airbags are much larger.  I didn't measure them but guessing about 3/4".

On my drive and tag axles, there are reducer fittings at the airbag to feed the 1/4" air lines.  I don't have ping tanks in the rear.

Thanks Frank. I gave Josam the part number and they will put 3/4" air inlet airbags on the front.