Technical 64 riviera vacuum for heater question.

So I got a 64 riviera and the console was out and all the vacuum lines disconnected. I found on the web all the hook ups and where they go besides 2 of them. A picture is attached. The black plastic piece. It is a diaphragm (plastic) piece with 2 lines coming out. 1 is large and adapts down to a smaller size. I cannot even find it in my manual. Any help is greatly appreciated.

 

Can you trace to where the vacuum hoses go to?

 

I ran all tbe others. Its the black piece and hoses in the pics they are only 6 inches long. Just can't see that in the pic.

 

The way to diagnose vacuum heater controls is to get a mityvac tool and use it t


o suck on the various vacuum motors and see what they activate. If the heater motor works, you can tell which way the air blows to find out what lines need to go where. Defrost obviously goes to the windshield. Heat goes to the floor.A/c blows through the dash,etc. If nothing happens, you have either a defective vacuum motor or some obstruction inside the heater/ a/c housing.

 

I understand how to test the diaphragm's . everything is hooked up the way it should be. Besides the 2 hoses/plastic piece in the pic. It is on the underside of the heater/ac controls. I don't know if they tee off into 1 of the other vacuum hoses. I took another pic for clarity.

 

Is there a part number on it anywhere? If so maybe you can look it up and see what they call it, to get an idea what it does. Try posting this question over on the Buick forum, someone there may know what it is for and how to hook it up.

 

knowing what the diaphragm does, will help with finding how to hook it up. put a vacuum pump on it and see what changes.

 

Just looked, no part number. Now put my mighty vac on the smaller diameter hose barb and the diaphragm sucks it. So I assume its going to connect to vacuum. The larger 1 does nothing with vacuum pump connected. the whole mechanism is actually connected to the ac controls. So switching the lever from side to side , low to cool pivots the diaphragm arm slightly. I figure they tee into 1 of the other vacuum line just don't know what 1's. I did just post on a buick forum. Hopefully I can get some info there.