I recently changed the expansion valve in the ol 420 sel and recharged with R-12 with three cans and the vent temps stay around 60 degrees when it's 76 outside with high humidity. I filled it up until full but still no change. This thing used to blow out 40 degrees at the vents no problem. What's the dealio?

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1984 300SD Orient Red/ Palomino
1989 560SEC
2016 Mazda 6 6 speed manual
1995 Ford F-150 reg cab 4.9 5speed manual