I called 6 more shops today. 3 were major national chains: Firestone, Midas, Sears, the rest were independent shops specializing in Auto AC. None of them had Nitrogen/ R22. To find leaks, all recharge with refrigerant/ dye/ detect with sniffer/ UV light.

Called up a welding supply. To rent a Nitrogen tank requires an account and cost $15 a month just for the tank, smallest size is 20 Cu ft, gas and regulator ($100) is not included. 20 cu ft of Nitrogen is $30. If you don't use it up, they don't give you a refund for what's left in the tank.

R22 is not cheap because it is being phased out by the EPA due to it being ozone depleting. Going rate on Ebay is around $50 for a 15 oz can.

A good electronic UV or infra red sniffer is $400 to $500. You don't want to buy a $20 sniffer from Ebay because they false alarm

For DIY, spending $500 to $600 for the equipment and gases to do Nitrogen / R22 testing just does not make sense. None of the auto AC shops use it. What does that tell you?

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85 300D turbo pristine w 157k when purchased 167,870 July 2025
83 300 D turbo 297K runs great. SOLD!
83 240D 4 spd manual- parted out then junked