My father tells me that the Air Conditioning in Sherman never worked, and it was like that when he bought it. He had the car in the Phillipeans and its heater core sprung a leak. Since the A/C didn't work anyway, my dad removed nearly all the Air Conditioning related items including the plenum, vent duct, unnecessary vacuum hoses, etc. So, over a few months I transferred all those parts over from a parts car I purchased. This section details how I got the interior pieces of the A/C system back in shape.

I started out the interior A/C restore by running new vacuum hoses to all the vacuum actuated parts. I found the old hose to be brittle and it would crack every time it was touched. The hose I purchased had a larger outside diameter but the same inside diameter as original. I wanted  to color code the hoses the same color as the factory did for ease of troubleshooting so I shot one side of the hose with paint. (I like to think of it as a really big stripe... I wasn't about to go through all the pain of masking a hose).

Here we see new hose hooked to the main control knob:

By the way, the main vacuum control switch is a little leaky. Buick did not design close tolerances. I have taken one of these apart, and it is basically three separate plates of metal with little tunnels cut in each wafer. As you move the plates, the tunnels connect allowing vacuum to pass. If you feel your switch is too leaky, you can separate the wafers and put new anti-seize between them which provides the closest to factory seal possible. Be sparse with the anti-seize, and use it just in the middle and outside. You don't want it pushing a tunnel closed once you combine the three plates. 


These are the new vacuum hoses shown under the dash. Down here is where all the action takes place regarding fan speed control, main vacuum vent, and STV setting (not shown). If you notice I have a spare main vacuum dump switch in place between the red and black hose for testing. The usual one is mounted on the bracket directly behind the one I am testing with.


I did have to have a little fun under the hood to get good vacuum to the climate control switches. On automatic transmission equipped cars, there is a nipple on the carb for transmission vacuum, and a nipple on the back of the manifold for climate control switch vacuum. The only problem is on my car I am running a manual transmission carb because it is one I bought and it works. Eventually I will get the original carb rebuilt, but that is big money to be spent down the road. That left me with only one vacuum port for two devices. Hmm... what to do? Install a splitter. I picked one up at the auto parts store and ran vacuum to both the transmission and vacuum ball. I checked with my vacuum gauge, and there was no discernable difference going to two destinations instead of one with the vacuum.

Vacuum tee shown right, vacuum ball shown left:


This was the next source of fun. I had to get this A/C distribution plenum....

Behind this dash:


After all the fun:

Putting the plenum in is a pretty interesting exercise. That is one of those things were you have to lay on your back and look upside down to do the install while stuff falls into your safety-glass covered eyes. Once you have the plenum in place, this large rubber gasket (looks just like a King-Kong sized black rubber band) is slipped over the connectors to both plenums to seal them.

The last step was to install the hoses to each duct. I had quite the time measuring the duct hose diameter. Even following directions on the ordering websites still resulted in not getting the right size hose. On the second try, I got it right, and it is a tight fit. The correct hose for my application was 2 3/4 inch I.D. I ordered it from It was $27 for six feet of it in 2006.

The passenger size and engine size of the A/C system is done. Now I just need to get the car down to an A/C shop to find my smaller leaks and charge the system with the R-12 I have on hand. At least now, I have blowing air instead of none!