Trying to get 72 Valiant AC to work

[gregpurcell]

It's a six cyl factory ac setup. It did not work when I got the car. It was not open however. It was an original r 12 system never upgraded. It was almost (but not completely) empty. I used the Duracool because it mixes with anything. With the compressor on and running (it IS turning) and the gauges attached I get about 70 psi on the low side (if I'm reading it correctly) and zero on the high side. I put a vicegrip on the heater hose to keep the heat out in case the heater control is not working. Obviously it's blowing hot air.

What do I need to change?

Thanks in advance!

 

[67Dart273]

Zero? You should at least read the static pressure even if the system is off. I don't know anything about "Duracool" and don't really like the sound of "mixes with anything."

My first thought is that your gauge hose is not depressing the high side service Schrader. Look into the end of the high side hose. Is there a depressor in the hose?

You have a service manual? You can download the 72 manual fer free in this thread:

http://www.forabodiesonly.com/mopar/showthread.php?t=132309&highlight=manual,+download

Check a pressure temp chart like this:

http://www.aircondition.com/pressure.htm

If the system was, say, shut off for some time, the car parked and cool, and you read 70 PSI this would indicate a staturated temperature of about 70*F. If the pressure is BELOW the temp on the chart, you have vapor and no liquid, IE the system is MT.

But that doesn't explain why high side readings are zero

Read the shop manual, then show us a photo of how you have the manifold hooked up

 

[67cudafb]

I think you have your hose hooked up backwards and still low on freon. Plus it has a leak or it would not be low. Need to fix it right and convert to 134.