'82 240D A/C question
 

Newbie here, why would the low pressure port spew oily foam when I remove the cap (to add 134A)? The engine was running with the A/C on. It hasn't been the same since I had to replace the compressor last year. Keeps me comfortable (blows about 55 degrees) but it's not what it should be (consistently 45 before comp change). New evap and dryer. Thought it might be over charged or have too much oil. Thanks

It will NEVER be the same with 134.

Your schrader valve is leaking is the reason it spewed out when the cap was removed.

There are tools designed to replace shrader valves without evacuating the sytem. I own one for R-12 systems. Don't know on a R134a...
Most ppl think the R134a convereded W123's don't perform nearly as well as the R-12 cars. You will want to rely the fan to run whenever the compressor is engaged.

Michael