AC cycles fast and doesn't cool well. I've had the car 8 years and the AC has slowly degraded so I suspect it has a slow (very) leak,

Considered converting from R12 to R134 but shops around here seem to be giving pretty high quotes even though I thought the '92 system was close to being 'R134 ready'

Anyway, after some research came up with Enviro-Safe which claims to be compatible with oils, seals etc and was thinking of trying this

http://www.es-refrigerants.com/resources/faq/


There is a kit which includes air enhancer (some form of lubricant I think) and a leak stopper. I see some positive comments on Envir-Safe as well as some negatives to this general approach (they recommend a full conversion)

now the questions:

1) Any experiences with Enviro-Safe ideally in a '92 240?

2) Where is the recharge port on the '92. I read a lot about the high and low ports being on the rear of the compressor but can't see them (haven't looked that hard yet, i.e. from underneath). There is a schader type fitting on the dryer (the cylindrical container near the passenger firewall) which has a black plastic screw on cover - is this the low side fill valve on the 92' vs being on the back of the compressor?

3) If I went this route, I think I need two cans of Enviro-Safe. What pressure should be on the low side?

4) Should I use the leak stopper and or 'air enhancer' or will they casue more trouble than they are worth?

Thanks