About 120psi will do you, but it must be absolutely dry otherwise it will contaminate the drier. You can use argon or nitrogen also. Just not oxygen or acetylene!! Or you can buy one of those cheapy a/c refill kits, just make sure it doesn't contain any magic sealants/lubricant booster/snake oils.
Yes, the O ring size is crucial, as it's not under pressure from the joint like it would be on something that's bolted down, like the acsd cover plate. It also holds the joint centered. Too thin and it won't reach across between the male and female part, and even if it's the correct thickness but slightly small id, then it will stretch to be too thin also. If you see what I mean.
If oil/dye comes out, then so does gas, just not necessarily the other way round. It's fairly safe to say that the evap is ok, as they're an extremely rare failure on toyotas.
Yes, the O ring size is crucial, as it's not under pressure from the joint like it would be on something that's bolted down, like the acsd cover plate. It also holds the joint centered. Too thin and it won't reach across between the male and female part, and even if it's the correct thickness but slightly small id, then it will stretch to be too thin also. If you see what I mean.
If oil/dye comes out, then so does gas, just not necessarily the other way round. It's fairly safe to say that the evap is ok, as they're an extremely rare failure on toyotas.