Running air bags at low PSI?

[Snowman9000]

(We are discussing Class C's here.)

I think most of us are kind of mystified over how much air to keep in our rear air bags.

We weighed our 2300 when it was heavily loaded including gas, fresh, and waste water, and it showed we still have another 2000 lbs of carrying capacity. We are not stressing the stock springs.

I've taken to measuring the bumper height with the rig empty and the air bags empty. Then measuring again after loading, and pump up the bags to restore the bumper height. I think that is the recommended practice.

Unloaded trucks are notoriously rough riding. So by restoring the unloaded ride height with the bags, are we in effect restoring the rough ride too?

I wonder if it is even necessary for mine. After all, the suspension is designed to carry loads. The fact that it squats down a bit while doing so is, well, what suspension does. To me, the unloaded height is not a holy grail. When we had a fiver, its pin weight brought my truck right to the payload limit. Yes, the rear springs squatted down a bit. But not so much that the truck was nose high. And, the truck handled it great.

Another comparison is to tire pressures. It is commonly advised that a motorhome owner should weigh his 4 corners, and find the heaviest side of each axle. Then look up the tire pressures for the two axle weights in an RV tire load chart. Then set the tires at those pressures, rather than the max pressure. This is for a more comfortable ride. I'm don't think the recommendations for air bag settings are using the same logic.

My 2300 sits tail high to begin with. I'm starting to question the need for the bags. Have any of you tried running very low PSI in your rear air bags? Did you notice a softer ride? Any change in handling?

[DocsDad]

When we had out 2300, it was significantly more stable in wind and with trucks passing with 45 - 55 psi in the bags. This doesn't answer your ultimate question though.

[grumpy0374]

The air bags are ment to raise the rear to a level position and to stabalize the rig , and to "soften" the ride. They will not increase the load capacity of your rig or it's suspension rating.
If your rig's rear suspension is rated for , lets say 5000 lbs, increasing or decreasing the psi in the air bags will not change that. Load your air bags up to 100 psi, and your rear suspension is still only good for 5000 lbs.
In your case with a short, light class c, your best bet would be to experiment with different psi's till you find a setting that gives you the most comfortable ride. If your rig is riding a bit "tail high" in the stock position with minimal airbag psi, than adding 20-30 psi probably won't raise it anymore, but may soften the ride, and stabilize it.
All the bag manufacturers recommend running at least the minimum psi, 5 psi.
A single "psi" is rated at around 40 lbs of weight load.
Grumpy

[Total Loss]

I would run minimum 10 (unless the bag will bottom out- that will kill it)
My 2251 weighed in at 10130 with typical stuff we leave in there and about 1/2 tanks. (water and fuel- no waste).
I have fully loaded mine and added 600 lbs to the rear (motorcycle and bicycles) and it handled great (actually better than without I think).
At 14,300 GVWr- I don;t really think you need air bags on these small rigs.
Look at the spring stack.

I want to lower mine in the rear so it is closer to level when driving.

[gmacklem]

I was running around 55 PSI after reading here. It leaked down to 45 and I ran that and felt like it rode better. So now I run it between 45 and 50 and feel like I get the softest ride at that level.

[brandon 2]

Yes, no matter how much or little air you have in those air bags it does not change the load rating. They are engineered for the ride not the load. We usually carry 50 in them and sometimes up to 60 , . This is fully loaded for camping. We do find that the rig is a bit more stable with the 60 in them.


Brandon2
2014 2500TS
Sun Seeker

[jtesta1]

Never run with empty air bags. They will collapse on themselves and wear a hole in the bag.

[brandon 2]

For sure why would one run on empty air ages/ They are engineered for a purpose
and as stated with no air they can be seriously damaged.




Brandon2
2014 2500TS
Sun Seeker

[Snowman9000]

Has anyone suggested running them empty?

[benagi]

I have seen that most of the people on this forum are always adding air to their bags because is slow leaks . Won't they leak all the way down during winter storage? Does anyone add air every month or two during storage?

[wahoonc]

Originally Posted by benagi

I have seen that most of the people on this forum are always adding air to their bags because is slow leaks . Won't they leak all the way down during winter storage? Does anyone add air every month or two during storage?

It won't hurt them to sit empty, you just don't want to drive with them empty because you will wear a hole in the bag.

I have a big, heavy Class C. We typically run our bags between 50 and 70 psi depending on loading. Lower for weekend trips, higher for longer trips due to the added load. I haven't gotten real world load weights yet, still working from factory numbers, seat of the pants and WAG. The ride is a bit better at the lower settings, crappy secondary roads don't help. It seems a bit more stable at the higher pressures.

One thing people forget is that the chassis is designed to ride best a given load point, determined by the OEM (50%?). We are running them at 75%+ of max weight which changes the dynamics quite a bit.

Aaron

[Wolverine 1945]

It would be nice if they would hold the psi we put in them !!!
I tried to check lines for leaks,,, ain't no way,,, unless you remove duels,,, maybe !!!

[wahoonc]

Originally Posted by Wolverine 1945

It would be nice if they would hold the psi we put in them !!!
I tried to check lines for leaks,,, ain't no way,,, unless you remove duels,,, maybe !!!

On mine the leaks are at the valve stems and body fitting. I suspect that it loosens up due to vibration. Not a big deal to check it periodically. Not like you are doing a space walk...

Aaron

[Total Loss]

Hey Snowman...did you add the airbags or did they come from Forest River with them?
I have not seen the smaller box C- Chevy's with them since they are on the 4500 chassis.
They really don't need them IMO.
The last 3 trucks I have owned- I put them on- they all needed them.
Not this MH- spring stack is HUGE. Almost seems too stiff even fully loaded.

[jtesta1]

Airbag can be empty in storage as there is no motion so the collapsed bag will not rub on itself.

[Wolverine 1945]

Originally Posted by wahoonc

On mine the leaks are at the valve stems and body fitting. I suspect that it loosens up due to vibration. Not a big deal to check it periodically. Not like you are doing a space walk...

Aaron

Valve stems can very easily be change !!!

[RvBill3]

My Chevy came with air bags. I usually inflate them to 50-55 psi. This is not to increase load capacity but to influence ride. I'm looking for a comfortable ride and also, the stiffness that the air bags provides helps with sway/push from passing trucks. I think the amount of air is largely personal preference and some trial-and-error. I'm glad I've got them.


2012 Sunseeker 2300 Chevy

[Snowman9000]

Originally Posted by Total Loss

Hey Snowman...did you add the airbags or did they come from Forest River with them?
I have not seen the smaller box C- Chevy's with them since they are on the 4500 chassis.
They really don't need them IMO.
The last 3 trucks I have owned- I put them on- they all needed them.
Not this MH- spring stack is HUGE. Almost seems too stiff even fully loaded.

They are standard equipment.

[W5CI]

Install an onboard air compressor, it will automatically add air when your set pressure drops

[wahoonc]

Originally Posted by W5CI

Install an onboard air compressor, it will automatically add air when your set pressure drops

I checked in to that... EXPENSIVE! I can use a $15 bicycle pump.

Aaron