I have to replace a leaky a/c hose, and I am considering doing a conversion to R-134. Coupla questions.

1. FCP Groton sells a Volvo parts retofit kit for $250. The kit includes, among other items, a new evaporator. Other kits make no mention of the evaporator. Is there something unique about the pre-1990 a/c units that makes replacing the evaporator necessary or prudent? This seems to be the most expensive component, and also the one that would require the most time to replace.

2. I've read up on the 700/900 FAQs on a/c conversions. (I'm also considering the retrofit on my spouses 89 740.) Are there differences in the systems, or is the 700 info a good guide for the 240.

3. FCP also sells a Scan Tech kit for $32, seems to include all of the necessary parts except the receiver/dryer, which can be had for $17.00. Anyone have any experience with this kit?

4. Is there a way to drain the oil from the compressor without removing it?

Any other thoughts or links would be appreciated.