I have searched online manuals and info, and so far haven't found the freon capacity for a 1991. I also looked for and was unable to find a label I could read on the car (mine is a J-spec, and most of the labels under the hood are in Japanese :eek:).

Anyone know the correct quantity?

Considering the cost of R12, and that you most likely have a leak after 18 year old seals, you are probably better off spending the ~$150-200 for a R134 conversion. Otherwise, you have to either just replace all the seals or buy a leak detector to find the leak which will cost maybe $20-40 if you do it yourself, and close to $100 if someone else does plus the $30/lb for R12, of which your car probably holds 3-4lbs. Weight that against the cost of maybe $5/lb for R134, and the fact that R12 costs only seems to go up more and more.

Just makes more sense...

+1

Freeze12, I use it in all my r12 cars, use freeze12 stop leak, and recharge with a few bottles of freeze12.. the whole kit is under $50 and is much colder blowing than r134a. I just did it to a friends e34 earlier in the week and it always works like a charm.

It's not colder, It takes less of it to be as cold.

Freeze12, I use it in all my r12 cars, use freeze12 stop leak, and recharge with a few bottles of freeze12.. the whole kit is under $50 and is much colder blowing than r134a. I just did it to a friends e34 earlier in the week and it always works like a charm.

Very interesting. There is another idea for ya, however just as a word of warning, ALWAYS evac the system instead of just simply charging the system. When an AC system leaks, it often times draws in air/moisture which rapidly decreases it's ability to cool, which can cause your system to become noisy and bog down on the engine. Even if you charge the system, the moisture will still reduce the cooling capacity, making the system work harder. You also do not want to over charge, as this will also cause lots of problems.

So Freeze12 probably is worth looking into, but do it right and evac the system before you recharge it!

Thanks for the suggestions. I'm in a little bit of an unusual situation - I have a large quantity of R12 and a R12-based a/c machine. I will vacuum the system and pressurize with nitrogen to locate any leaks. A new receiver/dryer will also be installed. I can recharge based on pressures, but it's kind of nice to know the correct measured amount...

Thanks for the suggestions. I'm in a little bit of an unusual situation - I have a large quantity of R12 and a R12-based a/c machine. I will vacuum the system and pressurize with nitrogen to locate any leaks. A new receiver/dryer will also be installed. I can recharge based on pressures, but it's kind of nice to know the correct measured amount...

good idea to pressurize the system prior to refilling it. Every REAL professional does it that way :)
I always found the AC condenser to be the rout cause for loss of gas. The aluminum just oxidizes over the years and can't hold the 10bar + pressure in the running system. So be prepared to buy a new condenser.