AC Oil Dye Injector R12 R134A Refrigeration Air Conditioning Oil Injector .

Tighten the inner and outer cylinders clockwise, then use a bit of 1/4 SAE threaded insert to expel a small amount of air from the blue tube. Connect the low pressure port of the refrigeration system to be refueled and add the required amount of cooling oil to the inner and outer cylinders.

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