Sounds like the pump is still capable, what was the ambient during the test?

And what did the low side drop from / to?

Outside of the basics like a little lubricant on the fitting threads, cleanliness etc, most of it is basic mechanical work. You have chosen R12 as a refrigerant, so there is no need to recalibrate the POA valve. Use mineral oil, check the oil in the compressor sump. I would drain the compressor sump...

LMAO Ice!

I am picturing an old Kysor roof box mounted on a new Ram 1500. You always make ne laugh. Good to see you back.

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That is a Ford / Eaton POA valve.

What are you trying to test?

Good place to start:

https://www.autoacforum.com/viewtopic.p ... poa#p17957

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Open the doors put the cabin fan(s) on highest speed and raise the engine RPM to 1500+ Observe the high side pressure at maximum load. If it is below 2.5 times the ambient temperature, temporarily block the condenser air flow and test again. If the compressor won't hit 300 psi on a 100f day it is ti...

Still in production, sixty million units later. You have choices. Do an oil change & flush, replace the clutch coil & go again if you like. It holds vacuum so the shaft seal is hanging in there. You could change the shaft seal when you do the clutch. You could replace the compressor with a r...

The SD7H15 is 154.7 cc/rev But like any compressor, shaft speed matters: https://www.sanden.com/objects/SD7H15_Performance.pdf The York was 210 cc/rev. On a gasoline engine. Overdriven from the crank, on an engine with a cruising rpm above the diesel's redline. 75-79 F series trucks had big evaporat...

The A6 with the flange for mounting in the A5 mount is not common at all. Hang on to that for sure. Flushing the oil from the compressor can be done without opening it. https://www.autoacforum.com/messageview.cfm?catid=20&threadid=12050 With an A6, you will need to drain & refill the sump wh...

Just buy a fresh York, and put it back together right.

That SD505 is a tiny unit. 90 cc/rev ? maybe less. The York is 210 cc/rev. See the problem?