What is marked on the top of the flange?
In what units do the gauges display? (like psi)

tandem-air
0-80 psi

Further inspection reveals knob is held on with set screw on the side and with the knob off I pressed the mini button in the center and got a small release of air, like from a valve stem.

quote:

Originally posted by MJ56:
tandem-air
0-80 psi

Further inspection reveals knob is held on with set screw on the side and with the knob off I pressed the mini button in the center and got a small release of air, like from a valve stem.

seems to be self-explanatory

When you turn the knobs and pull them out slightly, the air bags will inflate (assuming the compressor is working) Push in and turn to lock. The center button releases air.

Thanks, Steve
Now I know how to use what I am looking for.
I assume there are no bags on the tag axle.
Are the controls for left and right, or front and rear?
I have a pair of air "stems" near the bumper, front and rear. I assume these filled the air bags, I didn't know I had a compressor.
Are the stems for backup if compressor fails?
I looked for a compressor today, found what might be a small one on the passenger side of the radiator, top of frame.

Originally, there were air bags only on the tag axle and they were filled by using the dash controls and the front compressor. Dash controls are for the left and right tag bags. I replaced the compressor (see Rusty's post) I replaced the tag bags on mine, easy job... my tag was a Goodyear 1R9 038. I run 30psi (max is 50)

If you have additional air chucks there may be additional air bags on the drive axle. Follow the air lines from the chucks to see where they go. I installed bags on my drive axle, worked great to restore ride hide and soften the harsh steel spring ride. Drive axle.. Ride-Rite 2080 kit. I run 60 lbs of air. (Max is 100)

https://www.barthmobile.com/eve...1087061/m/9803910277

I checked and I have air bags on all 3 axles. Still no sign of a tank or compressor. I did verify that the small compressor near radiator is for the air horn, only one air line coming out direct to horn, I think. The mystery toggle is not running that compressor, I found out it controls the aux fan for radiator.
I tried to put air in the bags, to determine if tag bags were separate from rear fillers. I couldn't tell, I expected coach to raise as I filled bags. If it moved, it was very little.
No pressure to start with, small burst of air and it read 20 psi. I could get it to 100 psi quickly and then lower it 10 psi with a quick poke in valve stem. I left them at 60 psi. It seems there is very little volume of air required, is this normal? After filling rear, I checked dash gauges for tag and they still read 0. I guess it's possible they tied tag bags into rear axle. Is that possible to operate that way?

It is not recommended to run air bags without some air pressure in them. (Like riding on a flat tire)

I think the minimum pressure for the tag bags is 10 psi.

The drive axle bags are small and not much volume, they do inflate quickly. The tag bags are larger, hold more air. Try following the air lines back from your dash controls. One line on each will run back to the respective air bag, the others will combine into a common input. Follow that one back to find the source of air pressure.

I have bags on the rear axle of my '85 Regal which I inflate to 60#. There's a schraeder valve just behind the rear wheel on each side to accomplish this. It is tricky since they inflate quickly. Just a quick shot of air and then check. Be careful you don't overinflate because you could probably blow them up
Jim

While my Barth was in the shop for a master cylinder, I asked them to look at air bag system and find tank and where tag is plumbed, since compressor is not working and the other aftermarket bags have their own fill valves.

They found the tank and told me I had too much in at 60 psi and lowered it on front and drive axle. He told me he disconnected the line for output of compressor and (I guess) he tried to inflate tag. It wasn't clear whether he succeeded, so I left with the impression the tag had no air.

I got it home and looked at the lines going to the tank. I found one that goes in front of firewall toward A pillar so I assume that is going to the roof horn. I found what I think is another air horn mounted next to the tank. I haven't found an electric horn, unless this is electric also. The other air lines I saw went up through firewall, I assume to controls. I haven't traced any lines back to the bags. I now assume that the compressor would feed the dash control with air to send to the tank or release. Pulling the the knob out would activate a relay to run compressor. Another relay would be needed to supply air from the tank to horn. (air and or elec) I need another look to decipher these lines. My intent is to be able to fill the tank and tag bags from a mobile compressor, with or without dash control. Already looking for a fitting to recreate what the shop guy did at the compressor.

View is looking up from ground, under front bumper seen at bottom of pic, crossmember at top of pic.



I took it for my first time on interstate, about 40 miles. My conclusion is there is no air. The suspension or ride was ok, but when it went over a rise in pavement or a pothole, it would rattle the frame in the rear. Like Steve said, like a flat tire ... rim shot.
I have always noticed that going slow on a bumpy gravel road, it bounces up and down. Like the seat is on a spring like a bus or truck driver's.

Your photo is of a vacuum driven compressor and small air tank. On my coach they were inop when I got it. They were hooked up to horns only.

Your description of the air bag system function is correct, except mine had a separate electric compressor to provide air. It was mounted in front of the radiator on the pass side. The compressor had a pressure switch to power the compressor as soon as you pulled the knob out to fill the bags. I have since replaced both compressors with an onboard air compressor which I use for air bags, tire inflation and air horns.

Be sure to get those tag bags aired up before much use... not only will the tag bags bottom out and be crushed but the main axle is basically overloaded without the tag to carry some weight. Too bad you couldn't weigh rear axle separately, this would have been more obvious.

A clue that your tag bags are really low is that the tag brakes lock up and the tires squeal.

That is also a way to check if your tag brakes are working. Some owners do not maintain them and they stop working.

Thanks for the info, it's a great help.
If I understand correctly, the compressor on the right side is for air bags only and the output seems to go to the dash controls and I assume to the air bags from the controls. I also understand the vac driven compressor is for horns only and a relay would allow air to flow to the horn when horn button is pressed. I am guessing the electric horn would be on same relay, if it has one. Therefore, If I fill up the tank and relay is working, I should have air horns.

My next assumption is that when the tag control knob is pulled out, it turns compressor on and also allows air to flow to the bags. If this is correct, just putting air in where compressor was, won't fill bags until knob is pulled out. (Perhaps why the shop guy failed?)

Am I on the right track?
(EDIT) I think it worked ! I installed a fitting to go to the quick disconnect on my air hose. Set my compressor tank at 40 psi and pulled knob out, gauges went to 40 psi, pushed knob back in and locked, disconnected compressor and gauges are holding at 40 ... so far.

quote:

Originally posted by MJ56:

My next assumption is that when the tag control knob is pulled out, it turns compressor on and also allows air to flow to the bags. If this is correct, just putting air in where compressor was, won't fill bags until knob is pulled out. (Perhaps why the shop guy failed?)

When the knob is pulled out with the arrows aligned, it connects the bag to the pump output.

When pressure is where you want it, push the knob in and rotate it right or left.

The pump has a pressure switch that turns on the pump when pressure gets low, and shuts it off when pressure reaches the set pressure.

I overfill my bags and use the buttons to bleed them down to the desired pressure.

I have a Schraeder tee in the pump pressure line so I can air the bags from a tire pump or portable compressor if necessary.

Grrrr ... Driver's side dropped to 13 psi, passenger side holding at 40.