So I'm switching over to use R134a refrigerant and ordered the conversion adaptors. Replaced the compressor and clutch, dryer, accumulator and condensor. I find out that the high side adaptor is nothing more than a threaded coupling, open on both ends with a cap. Is this correct ? Anyway I found out that I'm leaking at the schraeder valve on the hi-pressure aluminum tube when I was filling the system with 134a freon. This may have been leaking for years as I was re-charging the system with R12 every season. Now I can't find anyone that carries R12 and they want to convert over themselves. You cannot find these OEM tubes anymore new. What I'm thinking is to put a plug in the conversion adaptor as one shouldn't be trying to de-pressurize the system on the hi-side anyway.

 

I, too, converted my 84 to r134 and had the very same leak in the same spot. I purchased a used tube on eBay from an 85 (still has r12 fitting) and was going to replace the whole tube and retro fitting. Problem was I didn't know for sure if the eBay tube was good or if it leaked at the valve too.

Long story short, I ended up using an aftermarket high pressure tube already fitted with the r134 fitting. Cost around 30 bucks and doesn't leak.

I still have the eBay tube if you want it (cover my shipping costs). You would still have to put a retrofit r134 high pressure fitting on it. Tube looks like its in good shape but I have no idea if it will hold pressure or leak.

Let me know if you're interested and pm me your address/zip and I can get shipping price.
Next time I get a chance, I'll shoot some pics of the tube as well as the aftermarket tube I actually used for my car. Not sure if camaro and Pontiac parts are interchangeable.

 

Did you use a Sanden compressor? I just put a new Sanden 5411 in mine, still need to get a longer serpentine belt and bolt. The reason I ask is that the tech article says to remove the pressure switch located on the back of the R4 compressor using snap ring pliers, but I'm not sure where to re-attatch it.

 

You need your hi-pressure switch to make your system operate correctly. It also controls your cooling fans through the ECM....I'n not familiar with a Sanden. I switched mine over to an OEM Delphi. You should have a port on your Sanden if it's compatible. There may be an aluminum plug behind the snap ring.

 

There seems to be a fitting on the back of the Sanden compressor below the suction and discharge ports. I'm not sure what it is. I've been trying to get some info on it but the closest description I seem to get is that it's a "service port." I guess I'll try to take it off and see if the pressure switch fits in it.

 

Here's some pics of mine with the new high pressure hose. It was actually fabricated at the shop that did the a/c conversion work. Costs for parts about 46 bucks. Works well so far.

 

Here's the OEM high pressure tube: (For comparison)

 

You should simply change to freeze 12 refrigerant. It takes the same oils as r12 so you don't change anything.

 

Be careful, those plugs are under pressure from the factory