I have a '93 Transport (surprised?), the previous owner had the mechanic alter the leveling system by putting a valve under the bumper to fill the air shocks. The air compressor was shot, so this was an economical fix. I am towing a tent trailer and have to fill the shocks via a gas station, and need to know how much pressure can these shocks take??? Any idea?

I had a similar set up for a while on my van, and was advised to maintain at least 20psi at all times, even empty to preserve the inner seals.
As far maximum, I have used 70 psi, but found 40 or 50 psi was adaquate for a tent trailer and 2 adults.
Jeff

Depends on the air shocks you have..

I have a set of Monroe Max Air shocks that are good for well over 100 Psi... The stock system I think maxed out at 70 Psi.. I have replaced the pump on my van as well due to failure of the original..