I have a high pitched sound coming from my panel/defrost door vacuum actuator there are two vacuum hoses attached to it. Not sure of correct name of actuator I have seen it called different things. It is located behind the glove box on top of the plastic duct box up by the firewall. While idling is when the sound happens and when I accelerate the noise stops. At idle my vacuum is 18 in hg at the passenger side vacuum port. I recently replaced the check valve on the passenger side of intake to see if that would help it didn't change anything. Is there a second check valve? A search of the internet says that the actuator is discontinued. I was wondering if anybody knows how to remove actuator, hoping I can maybe repair it. I don't see any clips or screws securing it. I am guessing the sound is a small pin hole leak in the actuator diaphragm. Does anybody know of a replacement actuator that might be close design that could be modified.

 

Best bet is to consult the parts manual, (and you can do that online) and get a part number. Then, google search on the number, and see what comes up. Likely have to go to the used market.

Take the lines off the actuator, and plug 'em. Noise gone? Probably a bad actuator. No clue how to get it off though.