Originally Posted by AFChap
What is the "balance tube" ?????
As for popping windshields out when leveling a coach, I know that is far more common than it should be. That doesn't change the fact that the mfg'ers of those coaches should be held liable for their faulty engineering, poor design and sloppy build quality. Such problems should be a very rare or never occurance.
Just kinda my way of describing the standard system used by powergear for the last 10 years or more.
Oil flow to the jacks is controlled by solenoids activated by the buttons on the panels.
"modern" powergear jacks have ONE button and solenoid feeding the front jacks.
Oil is free to flow from one jack to the other. As you jack the individual rear jacks to level the rig from side to side, the pressure will change on the front jacks, oil will flow from one side to the other until the pressure is again in balance. This is what prevents frame twist.
Worth noting that frame twist was only ever a problem if the jacks were used improperly.
This is still possible with the balance tube system. It has to be able to equalize. The jacks cannot be fully extended, no room for the high side to raise. And the jacks have to be extended enough to be holding most of the rig's weight off the suspension.
I carry 6 18" square, 2" thick plywood squares.
I use em under the jacks if I'm on a soft surface or on concrete or blacktop. Not needed on gravel. They are big, nothing is going to push the rig off of them. The extra pair is if the site is really off level, I can double up one end. This is overkill. The most "unlevel" place I'm ever in is my own driveway, it's low 8" front to rear, 6" side to side.
The powergear jacks will level it there. Generally with both the front and rear tire off the ground on the low side.
I don't know about other systems. The powergear jacks on my 1999 are BIG. Pistons nearly 3" in diameter, external retraction springs, 6 HUGE bolts holding the jack body to the frame.
The manual says it can lift the rig off the ground, and it does.
It's solid as a rock and ain't going anywhere.
I spend most winters living under my camaro, which is 2 feet in the air on 4 jackstands. These stands are not even bolted to the frame! It is considered to be a perfectly safe way to support a car.
Back to the question... Leveling procedure...
Park front low if possible.
Jack the fronts a minimum of 3 inches, but not so much that they are maxed.
Jack the low side rear until the rig is level
Jack the high side rear until it is solid to the ground.
Fine tune if needed. If the front jacks max out, dump em and start over
If the rear is low, I'd start by jacking the fronts a LOT, but not all the way up. If they hit thier stops, you can hit the dump button, let her drop a few inches, then turn the panel off and she will stop dropping.
Then hit the low side on the rear enough to level her comfortably side to side.
We mostly level for our refridgerator. And it's mostly concerned with front to rear. Operating the fridge much out of level front to rear will kill it, permenently, in maybe 36 hours. If it's close enough that you're comfortable in the rig, the fridhe will be fine.