AC Questions

[rcazwillis]

Trying to retro fit AC on Zane's 71. Compressor is from 2001 van that had a 5.7 vortec. At some point 25 years ago, the system was replaced. There is no high side port. Probably have more questions than I know yet.
New drier has label says flow with arrow. Which way does the flow go? From condenser or to condenser?
How much gas does the system need? I read where it depends on pressure in system when running. Can I get this from the port near the firewall (low side I think)?
How much oil do I put in?

[Steeveedee]

Are you putting in R-12 or 134? That will determine which oil is used. The drier goes on the exit side of the condenser so that there would be liquid in the sight glass. You can charge the system without a high side port, but won't know that pressure. You can buy a kit and install it for that port.

[rcazwillis]

It will be 134. Understand PAG oil is used. Is the amount determined by the compressor the size of the system? Seems it would be the amount of lines or amount of gas used.

So flow would be from condenser to drier. I think it is installed backwards. Will need to rotate it.

for high side, I will need a port that will go between two connections. Thinking at the condenser.

[Steeveedee]

The high side should be measured somewhere convenient, usually before the condenser. Oil will migrate, but only add the amount specified into the compressor sump for initial charging. do you have a vacuum pump, or access to one?

[rcazwillis]

Yes. Will have a pump and gauges. So the compressor determines the amount of oil.