Correct A/C pressure

I was wonderinf if anyone knew the correct way to test how much r134a you have in the system? My roommate just got all the equipment to charge his system and I think mine could use a charge as well. Its cold but not as good as it used to be. Anyway, we hooke up his guage and I was getting about 120 psi on the high side. Is this normal? Thanks for any help you might be able to give.

good question - what is the correct pressure to have on an a/c line and what is the diff in pressure b/t r-12 and r-134 - I know r134 is more pressurized but by how much


is it true that if u have no freeon (sp?) that there is a leak cuz the freeon (if no leaks) stays in there indefinately?

and they dont make the r12 adapters anymore right?

In NY you can buy R-12 to R-134a conversion kit at Wal-Mart - I installed one in my old car, and plan on doing my Integra this spring.