R12 to R134 conversion - use no more than 85% of the R12 weight. IE: if the old system used 28oz of R12, use 23.8oz of R134 max. The pressure differentials are too great for a 1:1 volume. We also need the PSI of the red zone. Without that, the pressure should be 'lower' - somewhere in the green or blue. Also, are you measuring on the hight side or low?

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1987 300D (230,000 mi on a #14 head-watching the temp gauge and keeping the ghost in the machine)
Raleigh NC - Home of deep fried sushi!