Yes you can. If PAG oil was used, be sure to get it all out.

And that's it? No replacing the expansion valve and the receiver/dryer? My coupe was converted, and the R134 is totally inadequate. Of course, the conversion probably did not include the evaporator and I know it didn't include the condenser.

I've looked at getting a parallel flow condenser, but if it's just a case of using different coolant, that would be better!

__________________
I never go far without a little Big Star

1994 E500 199/Gray 82k
84 300D (Salty) Orient Red/Palomino 141k
88 300CE (Ersatzhammer) 904/Java 163k -- Turbo Technics twin turbo kit, AMG Gen I body kit, Sportline steering box and steering wheel, Sportline/Eibach /Bilstein Sport/500E suspension, Quaife LSD in 210 mm diff case, Silver Arrow brakes.
88 300CE Brabus 3.6 199 on Black 44k

If there was any leak in your system, then yes, I would change out the receiver/dryer.

My 1988 300TE is black, and has LOTS of glass, so it get's hot inside, even with a nice tint-job.

My old mechanic converted it from R12 to R134a, and while fine for Santa Barbara, it's inadequate for Florida's heat & humidity.

I converted to ES-12 Industrial refrigerant (which is PAG oil friendly) and has pressure & temperature curves similar to R12, hence to get the optimum performance, I may try the "green" temperature switch, instead of the "red" one.

She gets so cold, the family complains if I keep it down for anything longer then 8-minutes

Once I get the aux. fan going, it's going to be even better in stop-n-go which has no airflow.

:-) neil

I mean, that's it, besides the stuff required to remove the oil. That means a new dryer for sure. Since the TXV must come off, replace it too. And of course, new o-rings all around.

The compressor must be flushed with appropriate oil.