Technical help please; Bishman bubble tire balancer

I snagged this balancer recently. Maybe it was the buy of the century or maybe it's money flushed down the toilet.

It's hard to see in the pic but there's an air connection right in the middle of the two legs just under the red cylinder. I've read that "air bearing" Bishman bubble balancers exist and I think that this is what I have. But I really don't have a clue. I've also read how an air bearing works.

NOW FOR MY QUESTIONS:

• do I just connect an air line to this?
• do I need a valve (foot valve?) in the line?
• what pressure does it need?
• can you "over pressurize" it?

40 - 50 years ago when I was in high school and college I worked in gas stations and tire shops. I've balanced hundreds (maybe thousands) of tires on bubble balancers. I was always the part time guy so all tire demounts/mounts/balances fell on my skinny shoulders. I know how to balance tires; I just don't know how this particular balancer works.

Any information appreciated.

Any truth spoken from experience especially appreciated.

Any opinions based on guesswork but not actual experience will be listened to and evaluated.

Any drama will be ignored.

Thanx in advance guys and gals.

Note: I'm sure that someone on here knows this thing inside and out and will provide answers to all my questions.

 

Anyone on the day shift know about these?

 

I have one ,it does need air ,I just turn the pressure up until the tire floats. I lift the top off and clean it good once in a while ,put a little grease on it to help seal the ball and socket so it does not leak so much . I love mine ,even made a wide 5 adapter for it from an old drum once.

 

You may be overthinking it too much so just do like JoeCool said. The air is just to eliminate the friction of metal on metal so use enough air pressure (flow) to do that. If you lined up a handful of those old balancers, I'd bet they all need a different air setting depending on crustyness, leakyness, etc. I'm guessing the weight of the wheel/tire requires more or less air, depending. Either it floats at a particular air setting or it doesn't. It will tell you how much it needs.

 

Thanx folks.

That's pretty much what I expected, but didn't know. Shoot, I'd not only never seen one before this one I'd never even heard of them.

Thanx again.