Air bag adjustment

[Markb5900]

Hi everyone,
I’m getting a set of Firestone bags put on my 1/2 ton.
Those of you that have bags, do you hitch up then adjust the air pressure or hook and unhook to adjust them?
Also, do you adjust them to bring the truck back to unhitched height?

Thanks!

[ARoamer]

I always kept 10# in empty and went to 28- 30# loaded. I had a on board compressor and did lots of on the road tweaking. I went for ride quality more than trying to level. You will have to experiment to find your setup's "sweet spot".

[CAG]

I had a different brand and the instructions were to keep 5# when not in use.


First order of business was to measure the rear bumper height unhooked. That then is the "fill to" mark. Once hooked up I then filled the airbags to the point that it brought the rear bumper back to stock. That keeps your headlights aimed properly for starters.

Once unloaded I dropped back to the 5# point again.
Once that is done you have a fill to number to air to without all the measuring.

[craigav]

I don't know if the leaf springs have changed over the years, but back when I had a 1500 and air bags I would inflate them just enough to have about a 1/2" of gap between the lower heaviest leaf spring and the lighter springs (leafs) above. This allowed for a smoother ride and any big bumps would land the upper springs on the lower and heavier leaf. This was close to being level all around but slightly lower than level. Also, anytime I traveled at night (rarely) I would air them up a little more to keep the headlights level, but I could always tell that the ride was a bit firmer than I prefer when doing that. ~CA

[craigav]

To add to my last comment, I aired up the bags after having the RV connected which had an equalizer hitch, but I didn't level the truck completely with the equalizer hitch so there was still some (but not a lot) of leveling that the air bags provided above what the equalizer hitch was set to. If I remember correctly somewhere around 40~45 lbs. I didn't have the truck weighed but once or twice, but I do remember that my axle weights were exactly were I wanted them to be. After you have your setup in place, weighing your axles with your rv can help you fine tune what will work best on your truck. ~CA

[Markb5900]

Thanks to all, it is appreciated!!

[Jace817]

I've read quite a few people in different places saying to air up to original ride height. I find that to ride way too harshly when I do that. I play around with it quite a bit, and even adjust for the road surface sometimes, but I'm definitely down from unloaded height. For my rig and trailer, I run 40 to 50 psi which is about 1.5" below unloaded height.

[Markb5900]

Thanks I appreciate it

[Russc25]

There are two questions here:
1. how much pressure to run when empty: as much as it takes to keep the bags from collapsing with the suspension at full droop... 3-10 psi. Collapsed bags are folded bags are ruptured bags.
2. how much presssure to run/how much ride height correction to aim for when loaded: this one kinda depends. To keep your headlights level, you want to get close to stock height. A little less might be more comfortable though. It'll also depend on the dimensions of the bags and springrate of the truck they're on. Wider low pressure bags are going to take less pressure and ride softer. narrow higher pressure bags are going to take more and ride rougher. bags on a half-ton may seem stiffer relative to stock than bags on a stiff 3/4 or 1 ton since they're so much stiffer before adding the bags.

[piperinv]

I may be slightly different from several people here since I pull a fifth wheel with a Reese Gooseneck box with my Toyota Tundra. I have my airbags deflated to hook up and then deflated to unhook. Since I use a gooseball, it lowers the height of the fifth wheel needs to be by an inch or two. (I deflate the bags before setting the front jacks of the fifth wheel.) It took me several trips to figure out the sweet spot with my airbags, but I tend to run them about 45psi with the trailer and 5 psi without. (Your truck/trailer combination will be different.) I have an onboard compressor, so I can change them as needed, depending on the road conditions. Hope this helps.

[CAG]

This really is another of those situations where every rig is different and trying to give advise for my situation may not be yours. I generally worked it out for my ride over time and that is what most probably need to do. Just saying.