Leveling on a GM (when parked)

[Geom]

I looked through the archives and saw some interesting posts about different methods for leveling.

The last post entry was a few months old and kind of stopped mid-topic, so I wanted to see if any new information is available.

I've heard that one can use/modify the built-in air level system on a GM to act as campsite levelers.
Anyone have experience with that?
Is it practical?
Does it work well enough to be usable?
Cost consideration?
Does it introduce wear issues later down the line?
How much lift/drop can be expected from a system like that?

If not using air leveling what other methods do you find most useful?

Are hydraulic systems an option?
Any concern with farme or body integrity lifting the bus off the ground that way?
Where would they mount?

Blocks?
Is that the only other remaining option?
Are they usable in a vehicle that's this heavy?
Any issues to keep in mind with them?

Any other clever ideas for leveling your rig while stopped?

[siberyd]

When I am parked for a long period, all air drains from air bags. If bus is level. Stays level.

I I am parked on a bit of slope, I block it so it stays level as the air drains from the bag. My bags empty after about 16 hours.

Siberyd

[Dave5Cs]

I separated air bags from braking system. Have push button controls Firestone ride rite. Each 1/4" line goes to each of the 4 corners 2 bags each on the air beams (which you wouldn't have in your GM). I can adjust each corner independantly and for level if driving.

Bags stay up as long as i want them too. Brakes fill faster also. air exhausts through the valves. each valve has a gauge on it. I generally have the fronts at 80 lbs and the rear at 90 Lbs.

You could get Hydrolic and they would be hooked up to the lifting points of the coach. Pretty pricey though.

Dave5Cs

[TomC]

I made my own leveling system that ties in with the two rear and one front leveling valve. Normally it is in automatic mode. When I turn it from automatic to manual, an either or air solenoid switches the air path from the automatic leveling valves to the two manual add air or exhaust solenoids. So each position has two switches-one for on/off (automatic/manual) then an on-off-on for up or down. Works well for quick over night leveling. But for stays of several days, I too will level the bus with blocks then just lower it down with the leveling system and be done with it. Good Luck, TomC

[sledhead]

My unit sounds like Dave5c unit     adjust it and it stays there until I change it . At the time 2005 it was $ 550.00  from h b industries                dave

[dellisor]

I have the same type but I have a older small 2 cyl compressor that I put inside an ice chest to keep it quiet and it maintains system at 120 psi and i have regulators on each corner sence my airbags are not leak tight.

[Barn Owl]

This is a DIY job. Not much to figure out. The PO of my bus did the simplest air system, but it has limits. The PO added a dump solenoid to every air bag and a solenoid to block the air leveling valves. A switch on the panel toggles between road and level with four "dump" switches to control the amount of air released from each bag. The problem with this system although a bit simpler, it lacks the ability to add air. Works well enough 90% of the time that I have not made changing it a priority. All I need to do is add another set of "fill" solenoids, switches, and some air line to complete it. Some get rid of their leveling valves and run off of pressure, another approach that also has pros/cons.

[technomadia]

We've gone two years using just wooden blocks for leveling, but eventually I want to rig a system so that we can manually override the ride-height leveling valves.

Hydraulic lifters are very expensive, and I've been told that they are extremely impractical to mount to the 4106's frame - making this a rare solution. Using the air suspension system to do the work is the way to go.

One other tip - rig things up as a tripod and not with four-corner control.  Adjusting via the corners has the potential to put a bunch of twist torque on the bus body.

Cheers,

  - Chris

[Lin]

We use a variation of the Robert G method.   We replaced the linkage to the ride height control valves with a push/pull cable.  When parked we can adjust the bag inflation by moving the cable.  To travel,  we put the cable back in its correct ride height position.

The downside is that you to have to exit the coach to pull the cables.  It also should be noted that any system dependent on the air bags has pretty limited adjustment.  I'd say only about 6 inches or so from front to back wheels.  For our 35 footer, that amounts to about one degree of rotation.  It works well enough most of the time,  but sometimes blocks need to be used also.

[Geom]

Thanks everyone for the good info.

It sounds like blocks will be necessary (or at least suggested) even with an air leveling system.

Dave5c, so is the Firestone system a completely different set of bags that would need to be installed, or will it act as more of a controller of the existing bags. I guess in your case they're new bags since MCIs (i think) don't have air originally?

For the folks that did a DIY type system, how involved was the install? Just simply install a couple of valve and switches or more involved? Since you'd bypass the builtin valves and such, do you have a different gauge to measure PSI or is the existing one still inline with this setup? I also assume it would involve some digging around under the bus?

Chris, thanks for the tip on setting it up as a tripod. That was one of my concerns, if it would cause uneven torque on the frame. I assume that means 2 corners on one valve, and two corners with a valve each? Does it matter if the tripod shared leg is front or back?

It also sounds like I'd be looking at ~6" of articulation total? Is that enough to make it worth it and practical? (I guess that'll obviously depend on where you camp, but overall...)
I assume that's a pretty hard set limit since the bags themselves won't inflate taller than that?

[sdc53]

PO put a set of 4 values and gauges on the dash to enable adjustment of each corner separately on mine.  The factory leveling system doesn't function anymore, and I wish it did.  I've seen this setup before on other buses, and it is effective for leveling any official campsite I've been in.  If you go with this type of system, just try and figure out how to retain the factory leveling functionality...

[TomC]

I'm curious if any that have converted their 3 valve automatic leveling to 4 valve manual have had any structual problems. There is a real good reason the OEM's only put one leveling valve in the front-to keep from having too much stress on the front corners from over inflated bags. Good Luck, TomC

[technomadia]

Chris, thanks for the tip on setting it up as a tripod. That was one of my concerns, if it would cause uneven torque on the frame. I assume that means 2 corners on one valve, and two corners with a valve each? Does it matter if the tripod shared leg is front or back?

GM's air suspension is set up with the front airbags joined together, and the rears working independently - making a tripod.

I think I've seen other buses (Neoplan?) where this is the reverse.

Regardless - keeping the tripod trait is a good idea.

   - Chris

[2xclutchin]

So, any suggestions on how to get the springs on my bus to help level?  Hehe

(Get it, no air ride! I'm sorry I have a dry sense of humor, and I had too. Now back to your regular programing.)

[Geom]

GM's air suspension is set up with the front airbags joined together, and the rears working independently - making a tripod.
...

Ahh, good to know, thanks.