I have Granning air suspension, and Firestone Ride Rite..how do they work?

[John USA]

1996 34" with tag axle.

I'm need to understand how these two systems function.

Each one of them discusses adjusting ride height. Why have two different systems?

Confused...

[subford]

You should have the Ride Rite 2068 as I do on my F53.
Here is the installation instructions for the Ride Rite 2068 and it should answer any questions you have about it:
http://riderite.com/-/media/www/ride...lManual_EN.pdf

I do not have the Granning air suspension on my unit./

[John USA]

Originally Posted by subford

You should have the Ride Rite 2068 as I do on my F53.
Here is the installation instructions for the Ride Rite 2068 and it should answer any questions you have about it:
http://riderite.com/-/media/www/ride...lManual_EN.pdf

I do not have the Granning air suspension on my unit./

Thank you, sir...what pressure do you run your's at?

[Cobra1]

I run around 50psi in mine when loaded. About 15 when not. Basically I adjust for rear ride height.

[tderonne]

We need to know exactly what you have. You obviously have two rear axles. Both with some sort of suspension. Haw many airbags do you have? Do you still have leaf springs on the original Ford axle? Are they mounted to the frame as Ford made it? Is the tag axle independent of the drive axle?

There are quite a few different tag axle systems out there. Even Reyco Granning has made different ones. They might have used Firestone air bags. Do you have an onboard air system? Is there a ride height valve?

Maybe you have some pictures?

[subford]

I run about 40psi in my 2068's.

["007"]

Here is info on Granning system if you need it found in QT's # 3 found under chassis suspension info.

[John USA]

Originally Posted by tderonne

We need to know exactly what you have. You obviously have two rear axles. Both with some sort of suspension. Haw many airbags do you have? Do you still have leaf springs on the original Ford axle? Are they mounted to the frame as Ford made it? Is the tag axle independent of the drive axle?

There are quite a few different tag axle systems out there. Even Reyco Granning has made different ones. They might have used Firestone air bags. Do you have an onboard air system? Is there a ride height valve?

Maybe you have some pictures?

Good questions...I found a compressor at the front of the coach, behind the grill. There are some unmarked buttons on the dash that I need to figure out. I found the owner/operator manual for the Granning, says it's RT500 series.

The introduction in the manual starts with "Air Suspension--What is it, and how does it work?", followed by a paragraph on "Roll Stiffnes", and lastly a paragraph on "Height Control Valve".

So, the introduction is all about Suspension, but half way through the manual it changes from Suspension to Brakes. I did see some strange components on the tag axle, so it looks like the Granning is doing dual purpose? Suspension and a secondary brake system..?

I'll crawl back under and take a second look.

EDIT: Ok, making a little headway on this. I got the compressor to come on, inflated the suspension, and raised the back end by a couple inches. I still haven't crawled under yet, I'll get to that this afternoon after work.

I'm assuming that you raise the rear end to help compensate for weight/loading, and to level the coach...is that right? Why do you release the air when parked? Is it to extend their life, don't keep the bags under pressure all the time, only when driving?

[John USA]

Originally Posted by tderonne

We need to know exactly what you have. You obviously have two rear axles. Both with some sort of suspension. Haw many airbags do you have? Do you still have leaf springs on the original Ford axle? Are they mounted to the frame as Ford made it? Is the tag axle independent of the drive axle?

There are quite a few different tag axle systems out there. Even Reyco Granning has made different ones. They might have used Firestone air bags. Do you have an onboard air system? Is there a ride height valve?

Maybe you have some pictures?

Ok....
How many airbags? Four. Two Firestone on the drive axle, and two on the tag.
Do I still have leaf springs on original Ford axle? Yes. Original frame mount.
Is tag axle independent of drive axle? Yes.

Couple pics:
Firestone Ride Rites on drive axle:


Bags on tag axle:


Vacuum booster for tag axle brakes:


Brake line to tag axle:


New caliper on drive axle:


I've also determined there is no air tank for the tag axle airbags. The system is console control (inflate, deflate, and gauge), compressor, and bags.

If they both contribute to ride height and suspension control, how do you know how much to adjust each set of bags?

Set the Ride Rites to 40, and then level it out with the tag axle bags?

[tderonne]

Quite a setup. I wonder if Rexhall put the airbags on the drive axle or not? If not, it'd be a simple matter of airing up the tag axle airbags until the load on that axle is correct (you should have the GAWRs on a sticker by the driver's seat somewhere). But with the bags on the drive axle, they'll add weight to that axle as you air them up. Then you'd have to add air to the tag. And of course the ride height goes up. Fun!