I would not suggest using a T to connect the bags together. As one bag is compressed and one is relieved the pressure in the compressed bag rises and the pressure in the uncompressed bags drops, now there is a pressure difference and air will flow from the compressed bag to the uncompressed bag. Therefor the compressed bag loses pressure and weight capacity.

This can take place in many situation such as an un-even load, cornering or while on a un-even road. It may not happen really quickly, but it will happen quick enough to possibly make things unstable.

I just thought id throw that out there,
i love the idea of air bags i just need to buy them and install them, but no money, yet.

 

Good thought there Fordman1090 it makes sense, but rather it true or not it is a possibility so why take a chance. I think I will just leave them separated. It would just be nice to be able to adjust them from the cab. It would be a bitch to be airing them up in a downpour, or blizzard.

I just had the chance to do my first pull today with the bags. It is definitely smoother with less banging than it was with those overloads.

I thought I was going to save some weight by removing those springs until I lifted that box with the air bags in it. I think I actually added some weight.

 

It would seem that some people here need to go over their intro to physics class again.

Your air pressure will not change at all since the size of the container (air bags and lines) does not change it merely deforms under load.

The only benefit of not having a tee in the lines is being able to air up each bag individually for a load that might be heavy on one side. Other than that there really is no point.

 

I just thought it would be easier to fill with one valve. That way the air would be equal in both bags. I would never load with an uneven load because the truck is only used to pull a fifth wheel. I just wanted to get rid of those heavy springs and see if I could smooth the ride out.

Our backs were really taking a pounding with those darn overload springs. When you get into the late sixties smooth is definitely better.

I did notice something interesting and when you think about it makes sense. I put 30 psi into the bags with out a load on the truck. When I connected the 5th wheel the psi went up to 45. So I guess the moral of the story is, "don't air up until your loaded," or "check the pressure after you finish loading."

 

I thought the tee would be a good idea until this past weekend at the sand dunes. I had my truck parked just right so the sun was beating drectly on one bag. Went to hook up my trailer and the truck looked cockeyed. Had 80 psi in the "hot" bag and 50 in the shady side. Let the hot bag down to 50psi hooked up and headed home.
BTW I have hex head valve stem caps on mine. Need a little wrench to take them off, and I have not had one stolen yet.

 

Like... biased weight?

 

Actually, that's not true :P Put a live-action set of pressure guages on your airbags and see. I can tell you that it definately changes. We're not talking solid rubber wheels, we're talking very small amounts of air in very thin bags; they don't just deform, they definately change pressure and volume. They act just like springs, actually, just like tires! I remember you claiming that tires under load don't change pressure either. They most certainly do! My bags can easily vary 10% over little bumps. 25% with bumps and heavy load, over the base unloaded pressure.

 

Airbags with a "T" in them will allow alot of body roll. As you turn a corner at road speed the weight transfer of the vehicle will try to compress the bag on the outside of the turn, with a "T" in the system it will force the air out of the bag and into the bag on the inside of the corner actually creating MORE body roll. Without the "T" the air has nowhere to go and stays in the bag.

And your air pressure DOES change, most truckers (myself included) use the air susp pressure guage to get a rough idea of how much weight is bieng placed on the tractor. You have to remember (from physics class) that a gas WILL compress and anytime you compress something it's pressure will rise.

 

Your speaking of pressure, which yes would remain RELATIVELY even in both bags if they were connected. However if they were separate and one side experienced a heavier load, it would, uinder that load, have more perssure.
What you forgot to include was the air's mass. If there is a tee then both bags would have nearly the same air pressure all the time, but if one had 2 times the mass of air in it as the other it would be 2 times larger.

Also the size of the chamber infact does get smaller as the axle moves towards teh frame. Consider also air springs that do not use rubber at all but pressurized air inside a cylinder, the is compressed by a pison which moves up and down (I have on eon my mountain bike).

At home science experiment, try it: get a packet of ketsup, hot sauce, mustard, whatever. Lay it on a table or other flat surface, press down with one finger on one end of the packet. You'll notice the liquid inside moves to the other end. The pressure inside the packet has not changed but the mass of liquid is no longer evenly distributed. I fyou move your finger to the other end and press down, the fluid will again move to the end where your finger is not.
Back to truck air bags.
Having the 2 bags connected with an open connection allowing free movement of air, would be like having one air spring only, in the middle of the axle. It would support weight but not provide any resistance to body roll.

For your homework, for this intro to physics class; make sure you know what your talking about before you try to give advice to someone.

 

Lets clarify here, we are talking about air bags and not air springs. Air bags don't have a cylinder at all as it is simply a big rubber bladder. The bladder, chamber, whatever you want to call it on an air bag will expand as you put more load on it. Think of a tire, when you load down your vehicle with more weight the tire will bulge more on the sidewall. When the air bag gets more load on it it expands more as there isn't anything around it to contain it.

 

Thats really all that needs to be said, were off topic anyway, and I see your opinion has already been formed.

 

O RLY? Lets do a little experiment. Put your tires to 40psi empty and then load down your truck. The pressure won't change as the size of the container doesn't change it simply changes shape.

 

Put it at 20psi and do the same test.

 

Sure, I can do that. The pressure will still be 20psi loaded. I can take pictures if you'd like.

 

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