We have a 93 4Runner, manual, 4x4, e liter V6. 10 years ago we Converted from r12 to 134. Recently the ac went out. Took it to Pep Boys and they did something for $50. I assume they topped it off. It works again. Cool. I bought guages, a leak detector, dye to track any potential leak.

What should my pressures be on high and low side for a converted system? I assume the factory r12 readings don't apply. Thanks for your help.

 

Not possible to say, as pressures depend on ambient temps. Google r134 temperature charts. Pick one.

 

Millball is correct; measuring pressures without temperatures is completely pointless (even though the parts-store a/c-in-a-can will tell you to do just that.)

Here's what I know about R134a conversions: https://www.yotatech.com/forums/f116...-r134a-284801/

Even though I measured recharge with pressures and temperatures, I've since learned that is considered to be second-best. The "right" way to do it is to recover all the current refrigerant, weigh it, and recharge to the specified total charge. (An R-R-R machine does all that automatically.)

As for the R134a temperature charts, it's actually built right into your gauges.

As you suspect, for $50 Pep Boys probably just "topped it off" (using one of those R-R-R machines). But refrigerant doesn't just disappear; you have a leak. Buying gauges was a wise choice. If you care, while deliberately venting refrigerant to the atmosphere is a crime, it's not illegal to top off a system with a known leak. Go figure.