Air Bags: To "T" or not to "T"....that is the question

We upgraded our trailer and even with an E2 WD hitch the ass end of the truck squats a little bit more than what i'd like. I just ordered the Firestone Airbags and Daystar Cradles (i dont offroad, but i also dont want to have to worry about ripping a bag if its on the lift). I also ordered the little T for the airlines, now i'm not 100% sure if its better to leave them independent or not, i see benefits of both ways:
Independent: can level it perfectly left to right (i have the trd sway bar in front/back), if a line blows at least you know which side.
Connected: only one air-up and both sides are good to go, bags equalizing pressure (not sure if this is a good thing or bad).

I'm leaning towards T'ing because with the rear sway bar, i'm not sure how it would handle it if one side was higher than the other.
I feel like there isn't going to be much difference either way, but wanted to hear some thoughts from you guys.
One thought was also to get a little shrader valve splitter that i could keep them independently and when i want to air them up together, i just use the 2-into-1 adapter.

I plan to use this guy that i bought about a year ago to have in the truck and never used it:

$32 AstroAI Tire Inflator Portable Air Compressor Air Pump for Car Tires - Car Accessories, 12V DC Auto Pump with Digital Pressure Gauge, 100PSI with Emergency LED Light for Bicycle, Balloons

https://smile.amazon.com/gp/product/B07QR4Q42L?ie=UTF8&th=1
To power the compressor, i'm going to use a 7pin to 12v adapter

$21 Reese Towpower 74681 Dual Port 12 Volt Power Adapter

https://smile.amazon.com/gp/product/B0016KH24U?ie=UTF8

Edit:
Daystar cradles easy to install?

 

I am firmly in the no-T camp. I don’t want to compress one side in a way that increases the pressure on the other side. That seems less than ideal and could maybe even make a big bounce worse.

I use a low-pressure gauge (0-20psi) to make sure they’re filled the same.

 

I have pretty much the same set up (bags, T, swaybar) and I opted for T right out of the gate, for simplicity sake.

 

I don’t have airbags in my Tundra but on my old Tacoma and 4Runner, I opted to NOT use a “T” for some of the same things you mentioned.

1.) I chose to keep the lines independent for if A.) I ever had a leak (likely in salt country) it would be easier to track down and B.) I have the ability to fine tune the vehicle. Meaning sometimes things don’t get packed perfectly.

2.) One less component in the equation. Knowing I drive it in salty weather…less things to fail. Plastic holds up much better to salt spray than metal connections. Cheap Chinese ones at least…loved the airbags but I was never impressed with the component quality other than the bags themselves.

Edit: Never regretted not using a “T”.

 

Every Kit I’ve installed the destructions say not to T.

 

I opted not to use the T for the same reasons provided above and to allow for the ability to fine tune each side independently.

I have airbags installed on my minivan without a T as well for 2 reasons. First is to reduce the squat when loaded (weak rear factory springs) and second, to act as a rear sway bar (no sway bar available) to reduce body roll. It has worked well for 10 years with no issues.

 

I am also in the "say no to T" camp for all of the reasons mentioned above.

Firestone says it's ok with a caveat:

 

I have both. I ran the AirLift Ridecontrols on my F150 independent with two separate valves. On my Lexus GX I ran it Tee'd. The airlift bags I put in my lexus do say you can tee them, I don't remember about my F150 bags. I honestly notice zero difference.

The thing is, if they are tee'd, the pressure has to remain the same in both bags which means they are going to continue to provide the same amount of lift. There is no way you can get more pressure on one side than the other going over bumps. Air might be able to flow across the tee, but the pressure remains the same, which is what matters.

If they are independent then I could see where the one side could increase under compression while the other doesn't.

In my mind, the Tee would allow the suspension to act more like it naturally would stock, just with the increased load capacity. Independent bags might act more like having a sway bar that wants to keep the two sides at the same height.

 

I chose to T mine. I can fill them simultaneously much faster, and since they hold such little volume it can be frustrating getting the pressure perfectly even between the 2 bags if they were independent. (I fill mine manually with a portable drill battery powered air compressor.) I opted for that benefit over being able to level side to side based on how the load is arranged. With the minimal payload these trucks have, I can’t see having anything in the bed heavy enough for this to matter for me anyway.

Also, the notion that weight transfer when cornering would compress one side and push that air to the other side doesn’t make sense to me really. If they’re T’d together then everything is at a common pressure. Compressing one bag does not change the pressure in it versus the other bag. 20psi in the common plumbing is always 20psi. Compressing one side won’t make the pressure in that bag lower and the other side’s bag higher. Sure the volume of the bag may decrease slightly, but not the pressure. The pressure in the bag is what is doing the extra lifting/supporting not the volume. (@ 20 psi it can lift 20lbs per square inch of the bag mounting surface).

This is how I rationalize it, I’m sure many disagree and that’s cool. Do what you think makes sense for how you use your truck. I’d only separate them if I was planning to put a significant amount of weight (like 600+ lbs) on one side of the truck and not the other which IMO is unlikely.

 

Thanks everyone for chiming in.

I think i'm going to not run a T, you guys citing the instructions specifically saying not to T them is what pushed me that way.
It just seems so much more convenient to fill them together. I may make a T adapter that goes after the schrader valves with a couple of these to air them up together

$10 AstroAI Air Chuck, Heavy Duty Closed Flow Lock On Tire Chuck with Clip for Inflator Gauge Compressor Accessories, Yellow

https://smile.amazon.com/AstroAI-Cl...sprefix=shrader+splitter,aps,118&sr=8-10&th=1

As far as the daystar cradles go, i guess they just mount to the lower plate that the bottom of the bag would normally mount to?

 

If you have a rear sway bar, it maybe safe to use T connections as far as one side compressing will push up the other side. The sway bar keeps the frame parallel or as close to parallel to the axle. It'll limit rear articulation for sure. But if you experience some instability particularly on uneven roads, then remove the T and go independent.

 

This man has science.

Pressure is the same when T'd, so one side isn't necessarily pushing the other. However when it's not T'd then as one side compresses it increases pressure and the opposite side will decrease pressure as it extends so it would tend to have a self righting affect. I run no T, on top of having a sway bar.

 

I should have been clearer. My thought was that when they are T-d together, compressing one side causes the other side to expand in order to maintain constant pressure. This does not seem ideal to me.

 

The ultimate install would be one single fill port with isolation valves on each side run of the T. Open the valves to fill both bags quickly and evenly, and if you are concerned about the minimal volume transfer between the bags then just close the ball valves.

 

i guess it depends on the goal. My logic with the Tee on my Lexus was that I want to occasionally carry more weight but still want the truck to flex well under load. It also comes with a huge KDSS sway bar.

so i think it really depends on how you intend to use the truck.

 

I thought about doing this also, but would be adding a lot more points of possible leaking.

An alternative of this would be a to have a line that would split the air from the compressor and go to both Schrader valves at the same time, then if you need to give one side a little more you can

 

I’ve been using “T” since 2009 when I installed my first set of bags, and towed thousands of miles with absolutely zero issues. I guess I’ve been extremely lucky or just too dumb to know I was doing something wrong. Good luck!!

 

I think if you are adding air, single air fill is the best. As one side drops in a dip the displacement would change if it was tee'd and so would the pressure. If you are running constant air pressure I would say Tee is best.

 

You have a good WDH why not adjust it, to make the truck level? The owners manual says to get the front of the truck at the same height before hooking up hitch and trailer. Just curious.

-Jason

 

I did the install today. Wasnt bad at all.
Only hiccup was that the brake line support comes off the axle ended up touching the lower bracket. No real way to bend it out of the way, since they should articulate together I didn't think it really mattered.

This was with 75psi in the bags to check for leaks.

 

Single fill with a "T" is fine if you use a check valve. Some people don't mind the loading and unloading as the suspension cycles, some do.

 

I use a AirLift Wireless One compressor, which is a single path (or Tee) setup. Zero issues with my TT or 20’ flatbed. Both are north of 7K# loaded. Before the TT, I had a big RTT on top of my canopy. Fully rigged with all accessories and with sleeping shit in it, it was every bit of 300# on top of the canopy. Never felt that it was a weird load with my airbag setup.
If I were hauling a big camper with a lot of weight up high, I’d do without the tee.