Any experience replacing HVAC actuators?

I have my HVAC box out doing the heater core and evaporator and I wanted to address something that has bugged me for a very long time, my defrost vents for the side door windows always blow air no matter what. The center defrost operates as it should and so do all the other vents. The foam seals all seem to be in good shape. So the only other option is a worn out vacuum actuator right?

The actuators work off vacuum. You can test them with a Mitivac or similar. Does the top flap in the heater box open and close properly when vacuum is applied? I believe its the middle of the three that control that flap and it has two vacuum lines because there is a "part open" mode.

md21722 said:

The actuators work off vacuum. You can test them with a Mitivac or similar. Does the top flap in the heater box open and close properly when vacuum is applied? I believe its the middle of the three that control that flap and it has two vacuum lines because there is a "part open" mode.

Click to expand...

I haven't tried applying vacuum since I have gotten the box out. Wasn't sure how to be quite honest but now that I know I can use the Mityvac I will call around to the parts store and see if I can rent one.