I have to ask before I do something potential stupid.

Since my 1995 Astro is running like a tractor with what I think is a vacuum leakage. I can hear a high pitch sound right before the 700 automatic changes gears.

Because of that I want to take out the Cheyenne and use it for daily drives to the store and to work, but I need to know If there is a risk to ruin something in the engine considering the pressure from the pump, and the fault code 18 ???

I would be really bummed if I managed to ruin something after pumping money and work in to the truck.