Air suspension again

[Jolly Roger]

Well it was finally nice enough outside to install the rear Addco sway bar and the Metco C/A's.
Problem is after supporting the car with jack stands and droping the rear end about 3 inches per the instuctions so that the factory control arms don't bind, I changed the arms with no problem but forgot to turn off the air suspension switch.
With the car back on the ground everything looks OK.
Just wondering if I have anything to worry about as far as air bag problems.
Opinions.:o

[Blk Mamba]

The ford dealer put mine in the air, without turning it off, till I asked, nothing bad happened, don't do it too often.

[Krytin]

You wont hurt the system - the reason for turning it off when on lift or jacking up is to prevent unexpected operation of the system causing possible unbalance or pinch points.

[rayjay]

You wont hurt the system - the reason for turning it off when on lift or jacking up is to prevent unexpected operation of the system causing possible unbalance or pinch points.

Thanks for that info. I too always thought it would cause damage.

[larryo340]

Going back to the many years I worked in a L/M service dept there were techs that never turned them off, and some that always turned them off. We never had trouble with the cars that had them switched off, but we did see some problems with older/higher mileage cars that the switch was left on. I'm sure that was due to the deterioration of the older air bags so when the car was put down off the lift the ass end would be on the ground due to the bags being totally deflated and out of shape. The fine cracking of the rubbler of older bags made it difficult to get them pumped up.

Just my .02

[ImpalaSlayer]

Going back to the many years I worked in a L/M service dept there were techs that never turned them off, and some that always turned them off. We never had trouble with the cars that had them switched off, but we did see some problems with older/higher mileage cars that the switch was left on. I'm sure that was due to the deterioration of the older air bags so when the car was put down off the lift the ass end would be on the ground due to the bags being totally deflated and out of shape. The fine cracking of the rubbler of older bags made it difficult to get them pumped up.

Just my .02


thats what i would think also. makes sence

[GetMeMyStogie]

Whether the switch is left on or not makes no difference in this case. The fine cracks you mention tend to occur where the rubber flexes the most, such as at the 'fold' (when the car sits at normal ride height). When the rear-axle is allowed to drop (such as during hoisting), the fold gets unfolded, and the fine cracks are allowed to open up, and the air leaks out - usually accompanied by a loud whooshing or hissing noise until all the air is gone.
Then, when the rear axle is raised to normal ride height again (such as when the car is lowered from the hoist) the air bags have no air in them to support the car. The car has to be turned on so the air compressor can fill them up. If the hoist is dropped all the way, the car will squat until the air bags are filled up.

Now, what actually happens if you leave the air suspension switch turned on while hoisting (allowing the rear end to drop) is the A/S computer will get a 'high' signal. If the car is turned on, or is on the hoist for more than an hour, the A/S computer will attempt to level the vehicle. Because it thinks the rear end is high, it will vent the system. This will have the same effect as leaky springs, except the venting will be much quieter - it will sound like the normal venting you experience when closing all the doors after parking the car.
The reason to turn off the air suspension is to prevent the A/S computer from doing anything. In other words, to prevent it from venting. That will keep the air in the bags until the car is off the hoist.