1975 & 76 Cadillac Temperature Sensor In Thermac Air Cleaner

[EAM 17806]

Here's a question that requires knowledge of the temperature sensor inside the thermal air cleaner.  There are two vacuum hose connections to the sensor, the question is does it matter which hose is connected to which one. Vacuum is provided from the intake manifold to the sensor which then is sent to the vacuum motor to control the damper assembly within the snorkel of the thermal air cleaner assembly. Some guys say you better be certain you get the vacuum hoses connected to the proper one others say it doesn't matter.  The shop manual isn't  specific about this so my guess is it doesn't matter.  What do you guys say? Incidentally, this is for a quadrajet carburetor set up. EAM

[Roger H]

I am sure their is a "right" way to hook it up however if the vacuum does not bleed through or leak out when hooked up, and if it does pass through to the other side when cold,  and it does  stop the vacuum when hot,  I don't think it would matter. 

[RobW]

Did you check the vacuum hose routing diagram in the service manual? I could check my 73 manual. The info might be the same for 74-75, but I'm not sure.

[EAM 17806]

I finally got the correct answer from a new AC GM original sensor in its box buried on one of my shelves with the proper directions as follows:  "Replacing hose connections. (Attach the hose from vacuum motor to the sensor nipple with the large orifice. Attach the remaining hose to the sensor nipple with the small orifice.)" You can't get any clearer than that but what bothers me is why the 76 Cadillac shop manual didn't state that since it is vital that the hoses get attached to the right nipple or the purpose of the sensor would render itself useless.  Well,  now we all learned something that was quite informative.  EAM