Does anyone have problems where under boost the AC seems to stop working in that air stops coming out the dash vents. I'm thinking that when intake vac turns to boost the pressure is closing the AC door. If I install a check valve to stop boost from feeding back into the line would that cause issues?

 

http://shbox.com/1/vac_check_valve.jpg

I don't know if 93's are different

 

I have went through 3 check valves in the last year. I am not sure if anyone makes a stronger one but if you find one post where you got it.

 

No problems here. The check valve works fine. Dash vents work fine.

 

Great! thanks all!