Were the ports on the back of the compressor sealed? if yes, ok. If no that is a problem. Early R4 compressors used O-rings at the back of the compressor, later ones used flat disc seals, you may need an adaptor kit but if you're having hoses made perhaps the adaptor could be avoided.

Ask the person doing the recharge to pull the vacuum/evacuate for several hours, this is how the moisture is removed, it decreases the boiling point due to the vacuum and the moisture boils out. Then let it sit for an hour to see if it holds the vacuum.

Next if they are an AC shop, pressurize the system with nitrogen to see if it holds pressure...nitrogen is cheap. If not AC specialists they may not have the nitrogen.

Good luck!!!

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