AC Update 79SC

[mholbrook38]

Well, just finished the update on my 79SC 3.0 air conditioner upgrade. I put a Seltec compressor, had new hoses made locally, new dryer and new valve. I installed it with R12, 28oz of Freon (R12). I'm getting 40 degrees at the lower vent which I also installed taking the place of the bow tie.

The worst part was the hoses obviously. 5 hoses, 10 connections. Sounds easy but is dirty and tedious. The worst were the two hoses that come out the bottom of the evaporator housing (smuggler's box). I had to jack both sides of the sway bar to hold tension and remove the heavy steel pan that also acts as the sway bar mount in the front. Even then it is hard to pull the hoses and push the new ones in. I had a busted line on the rear condenser that I had sleeved on the inside and braised. Sealed up OK. Couple of connections that were not as tight as they should have been but it pulled 26 inches of vacuum and I called that good.

So now the thing is to see how long it lasts. The vacuum was holding so I'm hoping it is good. Freon was not hard to find. It was only about $10 more a can than R134 is now.

Hope 40 degrees on a 79 degree day is going to hold up. I might have to add some more freon but going to hold off until it is good and hot out.

I ended up spending about $900 including freon using a friend's vacuum pump and gauge set.

[mlfox]

Good going! The A/C update I did on my SC was some of the best money spent to date.

Regards,
mlfox

[wwest]

Originally Posted by mholbrook38

Well, just finished the update on my 79SC 3.0 air conditioner upgrade. I put a Seltec compressor, had new hoses made locally, new dryer and new valve. I installed it with R12, 28oz of Freon (R12). I'm getting 40 degrees at the lower vent which I also installed taking the place of the bow tie.

The worst part was the hoses obviously. 5 hoses, 10 connections. Sounds easy but is dirty and tedious. The worst were the two hoses that come out the bottom of the evaporator housing (smuggler's box). I had to jack both sides of the sway bar to hold tension and remove the heavy steel pan that also acts as the sway bar mount in the front. Even then it is hard to pull the hoses and push the new ones in. I had a busted line on the rear condenser that I had sleeved on the inside and braised. Sealed up OK. Couple of connections that were not as tight as they should have been but it pulled 26 inches of vacuum and I called that good.

So now the thing is to see how long it lasts. The vacuum was holding so I'm hoping it is good. Freon was not hard to find. It was only about $10 more a can than R134 is now.

Hope 40 degrees on a 79 degree day is going to hold up. I might have to add some more freon but going to hold off until it is good and hot out.

I ended up spending about $900 including freon using a friend's vacuum pump and gauge set.

You might now wish too, QUICKLY, add a hi/lo pressure switch ($15-20) to prevent a refrigerant over-pressure with that new compressor.

[Joe Bob]

Where did you mount the condenser? I have a duck...the aftermarket POS used a turbo tail and mounted it underneath.

[mholbrook38]

There are two condensers in the stock system. The front under and behind the front bumper covered with a protective steel mesh and the rear condenser which is mounted to the engine hood hinges. I had to have the rear condenser repaired. It was half cracked in two and completely came apart when I removed the old hoses. I don't see how a duck tail or turbo wing would make any difference.

I have heard about these hi/lo pressure switches. Where do you get them and how do they work?