Ok. guys and gals, lets see if I am guilty. My wife complained enough about he air conditioning on our 88 240 so I decided to recharge it. I had R-12 hoses and had some freon. I had never charged this car before. However, the absence of cool air (yes switch was working) and the bubbles in the sight glass on the drier coupled with a tepid suction hose on the back of the compressor led me to believe that it was low. I hooked up the hose to the back of the compressor; to the outlet marked "S." It started drawing and getting cool. Then a loud bang. After quickly shutting the car down and going inside and changing shorts I came back out and located the problem. The hose going to the top of the condensor busted. My question is was this a problem of too much pressure? The way it sits in front of the raidiator I would not be surprised if it was nicked by road debris. Verdict please.
That said, I assume I will go R-134 now. For any that have converted, I am assuming I need to change the dryer and expansion valve and then get it evacuated. Any hints or ideas?