68 rs new actuators new hoses new vacuum valve nothing working at all. with car running you cant force the covers open. shut the car off and you can push them open as soon as you start they shut. That is the only action you can get out of this oem replacement junk. I am sure one of the new components is bad just have to figure out the right one. Does no good to switch hoses you get the same results the covers will not open no matter how you have the lines hooked up. Ready to send all this reproduction crap back where it came from.

 

Vacuum valve was bad had a hard time finding the corvette forum that gave procedure for checking valve with vac gauge. The new classic headquarters valve is defective. nice write up on how to check these systems.

 

Welcome, Histeel, and glad in reading you found the problem.
Hope the new replacement valve fixes it,
You'll have to let us know.
Correct year, BTW