Vacuum Control Switch Testing

[Les W.]

Hi, I'm getting prepared to replace my heater core. I know I have a vacuum leak within that area. Is there a procedure to test the vacuum control switch when I open up the console? 1972 LT-1 with air. Thanks Les

[Alan S.]

Re: Vacuum Control Switch Testing

Hi Les,
This diagram is from the 71 CSM but I hope it would apply to your 72 LT-! a/c controller too!
Note the chart in the lore left side corner.
Perhaps it'll be of some help to you.
Regards,
Alan

[Les W.]

Re: Vacuum Control Switch Testing

Alan, that definitely will help. I will need to test each port that requires vacuum based on the dialed location, along with the actuators to see if they hold vacuum. Especially knowing there is a leak somewhere in the whole climate control switching system now. In the process of replacing the heater core, I want to make sure when all is buttoned up that all the seals and the vacuum systems are tight. I purchased a heater core that was MADE IN THE USA, and it holds 35 PSI for over 24 hours---only the start. Thanks for the info on the chart. Les

[Alan S.]

Re: Vacuum Control Switch Testing

Hi Les,
Good!
You're right, getting the dash completely back together and then realizing there's a problem of some sort is something to try to avoid because the dash and console are a lot of work and quite fragile!
Regards,
Alan