ELC lowers when key off?

My Haynes manual indicates that the ELC exhausts air when the key is off. Is it intended to exhaust all air from the shocks every time I stop? It doesn't make sense to lower the vehicle every time I stop for fuel etc.
With over 200k miles on this can it's amazing that the compressor still works.

The ELC is designed to maintain a certain level, and will exhaust air when key is off to maintain that, IE, when load ( passengers. cargo) is removed after the key has been turned off. When load put back in, compressor will turn on as required once key turned back on..if sytem functions properly. It should not exhaust all the air when key turned off
Jeff

When I disconnect the rod attached to the axle and push it up to simulate a load it pumps with the key off but when I return the level switch to the level position it starts to exhaust as soon as it stops pumping. It doesn't maintain any pressure. I was trying to raise the vehicle to see if it would hold the pressure. It seems at a level position such as when only the driver is in it, it doesn't maintain any pressure and the ride is bouncy.

...what year model is that ? Mine ('93) kept the pressure (according to load) when the system was operaitonal.

My van is a 96 Trans Sport SE. With no load it sits level but the shocks are deflated. I'm wondering if the level switch is defective or out of adjustment and it's sensing that the van should be lower. Is the rod connected to the axle adjustable? I was thinking of pushing it up a bit to see if it will maintain a higher ride height.

Following taken from 95 manual:
there is a 8 to 15 second time delay before compressor will begin to inflate, or also to deflate. There is also a check valve in the exhaust valve to maintian 7 to 14 PSI in the system minimum.
Where are you hearing the air escape? Should only be at the compressor, located behind the left rear wheel, in the lower inner fender. If you hear air escape right away, you have a plumbing leak, the connections at each shock and the air bladders internally in the shocks are problematic, as well as the hoses
Jeff

The air leaks out at the compressor. Just a gentle hissing sound after the compressor stops and the shocks deflate. I guess I'll have to adjust and test it with the engine running to be sure that it holds the air. The shocks are supposed to have a min of 10 psi to prevent damage.

As far as I know, it shouldn't exhaust, just because the key is turned off......

When you disconnect the level sensor arm and you raise it slightly, about 1", after a delay, the compressor should run and the level of the vehicle rises....let's say it rises 1".......the compressor should shut off.......and the solenoid should not open and exhaust the system.....when you then lower the arm, after a delay, you should hear the solenoid click, and then hear air exhaust, and the vehicle lowers....

Is it possible you have a slow leak, and that is why it drops?

... The shocks are supposed to have a min of 10 psi to prevent damage.
Yes...to keep the rubber jacket from rubbing against itself.
My compressor and control unit have been shot a long time ago...with all the winter salt here...and I have replaced it all with a 10$ 12v compressor ....that I run regularly from the 12v accessory plug to ensure maintaining minimum pressure (it has a pressure gauge...so easy!).

Well, I determined whether the key is on or off it pumps if the level drops too low but there's a very slow leak. I soap sprayed the shocks and didn't see any bubbles so I'm thinking it's at the pump somewhere. I think I'll change it over to a Tee with an air valve so I can pump them up manually and see if they still leak down.