OK, I got some R12, thanks to Larry.  Can someone send me step by step instructions to re-charge.  Cannot find my old notes.  I have the origianl service manual, it was written for shop workers back in 79.  When I paid someone the last time I did it he put the R12 in at the top of the dryer, there is a fitting near the larger line that goes into the evp/box.  I do not have a site glass.  Fitting near back of compressor also, goes to top of dryer, large line.  3rd fitting on small line that goes to the condensor, front of car. 

dang dude i wish i could help you the only way i have ever charged a car was to vac the whole system then weight in the charge i have never had much luck with just toping off the system and what kind of pressures you will be looking for sorry

You can use the fitting on the compressor OR the accumulator/dryer for the low side hose.
The small, metal line is the high side. the fittings should be different sizes, also, with the larger of the two being the low side(suction), and the smaller fitting the high pressure.
Are you just topping off, or doing a complete re-charge? If the system is empty, you really do need to have it evacuated first. If it is still cooling, but just low, you can add to it with no problems.
You want to see about 30 psi on the low(suction) side, and around 200 or so on the high side. You should have a fan of some kind blowing thru the condenser while doing this, to help keep the high side pressures down.
If you do not have any gauges, be very careful!!! Too much freon will lock the compressor up, or pop a hose. Neither will make your day...

I was just going to top off.  The system is barely cooling, compressor cycles allot. This will be the third time I do it since I restored the car in the early 90s.  Nothing has been done to the system.  I let it go for a long time has been needing a topoff for some time now.

Ambient temps do play a part in how much freon the system will need. You can tell if the system is low just by connecting the gauges to it, and checking the static pressures(before running the engine or the A/C). The system pressure should very close to ambient temperature. For instance, if it is 80 degrees outside, then your system pressure(static) will also be around 80-85 psi. If it is 100 deg outside, system pressure will be in the high 90s for psi. Just a quick way to see if the system is low on freon.

Thanks for all the help Joel.

Joel please review my notes and let me know if I have it right?

Well I tried it, clearly I don't know what I am doing, good grief : (

It all looks fine, except you want the A/C on High, and high blower.
Is the compressor kicking in at all? If it is really low on freon, the compressor will not come on, but adding some freon to it should cause it to kick in.
The gauge hoses are usually color coded. Blue for low side/suction, red for high side/pressure, and yellow for intake from the can/jug. Only open the valve on the LOW side of the gauges...NOT the high side. Opening BOTH can cause high pressure to be pumped into the freon can, and cause it to explode!! The only real reason you would ever want to open the high side valve would be to equalize the high/low side pressures after charging, or when evacuating the system.


When you're done, close the valve and let the system equalize before removing either of the hoses. This will allow time for the pressures in the hoses to lessen, making much less of a mess when you disconnect them. The middle/feed hose does not need to be removed from the gauges, or the can.
Adams' Apple2010-09-27 10:20:20

Yes the compressor does cycle.  I was opening both sides and the low side pressure would go very high when I opened the valve on top of the R12 can, releasing the freon.