Well the first thing you need is a good cheep …and I do mean cheep….. vacuum pump.
So a night on the town with your buddies (beer Optional ) is in order……Scope out the neighborhood for an old refrigerator on trash night…
When you find one….and when nobody’s lookin…. Carefully extract the compressor……
like this one….
Fig 4063
Solder a schrader valve fitting, to the suction side, wire up a power lead and an on / off switch as shown.
If your system is charged you need to discharge it. This can be recovered at a local shop if you choose.
After you discharge the system you want to check the oil level in the compressor.
Connect your gauge set and the vacuum pump to the system and evacuate the system. A vacuum pump removes troublesome moisture by lowering the pressure within the system and vaporizing (or boiling off) the moisture, then exhausting it along with air. Let it run till it gets to 29 inches of vacuum.
Then close off the valve and observe if the vacuum drops down. This would indicate a leak …let it set for a half hour.
Ok …no leaks …. Turn on the pump and let it run for several hours or more…
Next
You will need a fan in front of the car to keep the air flowing
Fig 4057
In my case the system needs 4 lbs. of Dichlorodifluoromethane Freon 12 so I converted it to 134A.
If you do, you only need about 85-90 percent of the charge. That’s 64 oz. of 12 vs. 55 oz. Of 134A.
Fig 4059
Use your gauges and temperature chart. Observe the Ambient temperature and the temperature of the air coming out of the vents.
Fig 4061
It was 93 degrees outside and I got 47 degrees out of the vents before it was fully charged on a black car.
That's basically it!!
You can do this because the oil is resident in the compressor sump and does not flow through out the system like on a modern vehicle.
