pmckechnie,

Yes, I did not know you were making a joke. Things are easily taken wrong from written text. It's a testament as to the importance of body language.

The chart I have indicates 2.66 pounds of R12 for your '84 500SEL. This is not factory information, but it is probably pretty close.

That said, R12 is not near as fussy about having an exact quantity as is 134. If you get it a little over charged, it will accumulate some in the r/d. If you can achieve about 22 low side and about 250 to 265 high side in 80 degree ambient with a fan in front of the car, engine at about 1500 RPM and after about five minutes for pressures to stabilize, you should be okay.

lyonstexas,

If you change from 12 to 134, you will be better served by using 134 compatible o-rings. These o-rings are good for BOTH 12 and 134. Used to these were green, but now there are 134 compatible o-rings available that are black.

You can get a very good assortment for about$25 from ackits or acsource and it comes with nylog seal lubricant. If you will doing even a small amount of auto air work, this will prove to be a good investment.

Good luck,