Ok, I can't tell you for sure the temperature of the air each time I've tried to lock and unlock my car but why would it work sometimes and not others?
If air contracts when it's cold and expands when it's warm isn't it possible that air in a vacuum system would do the same?
I posted earlier about being frustrated with my hatch lock: I had the tailgate apart, adjusted the actuator "away" to take up any play. I also disconnected and plugged all vacuum to and from the gas cap. Everything seemed to be working fine so I put it back together again~
Now it is working inconsistently.
Any assistance would be appreciated, I have performed a search on this issue but would like to avoid buying a MityVac and tearing apart my doors, etc.