Firestone Ride Rite cab controls

[Rocinante Sunrader 88]

I have a 1988 Sunrader with a factory installed Firestone airbag system that has an onboard compressor and cab control. Per my paperwork, the control system was made in (at least) 1986 and the system is "Cab Control Kit W21-760-2018. When I got it the compressor and cab control were disconnected, both physically and electrically, but despite the fact that the airbags had had no air in them for ten years, they held pressure fine when inflated from the valves on the outside of the coach. I do, however, want to have the cab control system working, as I want to be able to use it to level the vehicle when parked.

The compressor has a failed pressure switch, but when I wire around it it puts out air fine and fills the tank and the shocks. My problem is that when I try and use the cab controls all that I can do is push the button on the center of the knob (see picture) to let air out, and it lets air out of both sides, no matter which of the two buttons I push. I am sure that this is not how it is supposed to work.

I am pretty sure that I have the airlines running right now. Basically I have a line from the compressor to the tank, from the tank to a tee that goes to each o9f the two control valves, and then from each valve back to the back, where each one hits a tee that connects to an airbag on one side and to one of the two outside valves on the other.

Does anyone either have one of these systems or better yet, have either installation instructions or operating instructions for this cab control system? Firestone is no help and google has gotten me nowhere. The cab controller consists of two units, each of which has a pressure gauge and a knob with a button in the center of it. Pushing the button releases air from the system (from both sides at once.) I can pull the knob out and then it will only turn about 15 degrees or I can push it in and it will rotate freely, with no right or left limit. All that seems to do anything is pushing the button in the center of either knob.

It's dark here in Watsonville, I'll try and put pictures up tomorrow of the cab control units.

Thoughts?

Edited December 18, 2010 by Rocinante Sunrader 88

[Rocinante Sunrader 88]

Here's a picture of the cab control unit, if that helps.

[WME]

Sounds like you need a one way check valve between the t and the controller on each side.

[Rocinante Sunrader 88]

Sounds like you need a one way check valve between the t and the controller on each side.

Good idea, but it's a bit of a clumsy workaround. It seems like the controllers are delivering whatever pressure is in the tank to the airbags. Even if I have check valves, I would have to fill the tank up high and then bleed down to wherever I wanted to be. If I needed to put any air back iinto either airbag, I would have to start up the compressor again, bring them both back up, and then start bleeding each down again.

[Gulfstream Greg]

I think there is supposed to be a valve switch that directs the compressor air to which ever side you want to inflate. Here is a link to the Air-Lift one, looks like there is a check valve on each line from the compressor and so both get air when the compressor is on then you adjust by letting air out of one side. http://www.airliftcompany.com/manuals/MN-337_25812.pdf

[Rocinante Sunrader 88]

I think there is supposed to be a valve switch that directs the compressor air to which ever side you want to inflate. Here is a link to the Air-Lift one, looks like there is a check valve on each line from the compressor and so both get air when the compressor is on then you adjust by letting air out of one side. http://www.airliftco...N-337_25812.pdf

Thanks, the diagram is helpful. I think I have it figured out now. I'm stoked!

No check valves in the system.

Each gauge shows how much is in that side on the airbag end of the circuit.

When I have the arrows on the know straight up then it just allows whatever pressure is in the tank/compressor side to go to the airbag. When I turn the knob so the arrow is down it seals off the line and I can bleed down from there on the airbag side of the control valve by pressing the button in the center of the knob. So basically the knob is a valve that is either open or closed, with a bleed function on the center button.

The reason that I could not get the two sides to operate independently was that I had both of the knobs in the arrow up position, so both valves were open and bleeding either side bled the whole system..

Now all that I have to do is order a pressure switch and I'm good!

I'm hoping to get this thing out on the road for the first time after the new year.

Edited December 19, 2010 by Rocinante Sunrader 88