Hi
About 2 years ago I changed both the check valves in the engine of my 88 760 T-Wagon.

Now my a/c vents quit blowing when I give it a good dose of gas. They work fine again after you let off the gas. I believe this is a vacumnn related problem and especially related to those check valves, I can't believe they are both bad again.

It looks like the rubber boots going over the valves and recieving the hard vacumnn lines are awfully soft (88 original) do you think I could be getting vacumn leakage under load from the sides of these soft boots while accellerating?

Are there any other reasons that this condition may occur?

Thanks!