[Slowguy]

Wanted to help but read some confusing stuff here. You are reading psi always. The red r-12 scale tells you what your suction temp “should” be at that specific pressure. You use a scale to check what that should be specific pressure given and specific temperature.

You said your suction line is sweating. That is good. Do you have adequate airflow inside that cab? Do you have adequate airflow across your condensing coil? The high pressure vapor line going into the condenser should be very hot. You shouldn’t be able to keep your hand on it at all. The line coming out of the condenser should be much cooler but still warm. This will let you know if the condenser is adequately removing heat.

Are you sure you aren’t overcharged? Those pressures don’t seem that far apart but usually if a compressor is bad you don’t see much differential between the suction and liquid side. My guess is overcharge. I’d charge it right to the point where your sightglass bubbles disappear. Then your done. This is assuming the expansion valve has had time to equalize.