Air 'Bags' - too lift or not to lift

[JourneytoRet]

What is the purpose, hence (I finally get to use that word in a sentence) use of lifting/lowering the MH?

[masseyfarm]

The 'dump valve' on your motorhome is to be used, when parked, to lower the unit and allow easier access in and out.
It also allows a solid base when parked on level ground to be able to 'camp' in the unit without putting the legs down. ( ie: WW or other paved lots that the legs would punch a hole in the pavement if deployed. Never deploy the legs on pavement without placing heavy rubber pads or plywood to distribute the weight.)

Some of the newer units are leveled only by the air bag system and do not have hydraulic jacks.

I am at present in the process of plumbing my air system on the CLIPPER to be able to lower the front and back suspension independently so if I was caught in a traffic tieup on some of our mountain 8% grades, I would be able to level the unit enough that the fridge could still run without frying it. (I like my beer cold!)

Dave

[adonh]

Would the dump valve be the the switch located to the left hand side of the instrument panel in my XL396. Mine has a semi cover over the switch. I have never touched it and have always deployed the hydraulic levelers when parked in the camp site. Once level I then turn off the engine and move out the slides. So if I wanted to lower the coach while parked in a level spot that may not be suitable for using the levelers and therefore no slides I could "dump'' the air bags. Is that correct, or I am I off base.

Thanks

[masseyfarm]

On my Clipper the air dump control is located on the right side of the steering column on the lower dash as seen thru the steering wheel in the attached image.
I don't have a clear picture of your dash Don but the faded picture shows something similar on the bottom left of your lower dash.

You would normally dump the air before deploying the jacks as this will get you lower to the ground and require less lift from the jacks to level.

After dumping the air it is imperative that you deploy the front jack first to take the unit up 3 or 4" before trying to level with the rear jacks.

When you dump the air, your unit is sitting on the axles and there is no give left in the suspension. If your try to level the coach from the rear, without raising the front first, you will twist the windshields out of the unit.
If it requires even more level, then you must lift the front more so that it does not contact the axle, thus twisting the body of the unit.

For ground pads for the jacks, I just cut up some heavy matting, (similar to what the contractors use in the pickup trucks,or horse owners use in their trailers,) and drilled a hole in one corner. That way I can maneuver them into place with my awning rod. On my unit I carry them in the bay below the LPG tank.

Dave

[adonh]

Originally Posted by masseyfarm

On my Clipper the air dump control is located on the right side of the steering column on the lower dash as seen thru the steering wheel in the attached image.
I don't have a clear picture of your dash Don but the faded picture shows something similar on the bottom left of your lower dash.

You would normally dump the air before deploying the jacks as this will get you lower to the ground and require less lift from the jacks to level.

After dumping the air it is imperative that you deploy the front jack first to take the unit up 3 or 4" before trying to level with the rear jacks.

When you dump the air, your unit is sitting on the axles and there is no give left in the suspension. If your try to level the coach from the rear, without raising the front first, you will twist the windshields out of the unit.
If it requires even more level, then you must lift the front more so that it does not contact the axle, thus twisting the body of the unit.

For ground pads for the jacks, I just cut up some heavy matting, (similar to what the contractors use in the pickup trucks,or horse owners use in their trailers,) and drilled a hole in one corner. That way I can maneuver them into place with my awning rod. On my unit I carry them in the bay below the LPG tank.

Dave

Yes, the dump control in mine looks just like the one in your Clipper and is located on the left of the instrument panel. The 396 XL has the Power Gear leveling system with both manual and automatic functions. After reading the operating manual it states.

• When operating in Auto Mode, there will be a 20 second delay before the jacks begin to extend, while the air dumps from the vehicle suspension.

• When operating in the Manual mode air will be dumped from the vehicle suspension in approximately 20 seconds

So the air bags are dumped before the leveling process begins which does lower the coach. I have always up to this point tried to park in what appears to be level parking spaces and used the automatic leveling process. Something that I did not realize was that in the automatic or manual leveling process no wheels should be off the ground. Although the parking space I am in now appears to be level the rear drivers side wheel is off of the ground about an inch after the automatic leveling process. The coach is level. So I guess I need to either pull forward or back up until I find a more level area in this parking space. Or could I try lowering the jack on that wheel manually until it touches the ground.

[masseyfarm]

There is no concern about the front wheels being off the ground other than you will have a big step in and out. If you were parked in a regular spot, you could have a portable step to accommodate that difference in height.

The concern is, if both rear wheels are off the ground, you will not have rear wheel end brakes on yours. (If you had a driveshaft brake, one wheel elevated would compromise the brakes ability to hold the unit.)


Dave