Do I need to remove old freon in order to refill freon and get my ac cold in a 98 Chevy s-10?
No , but if you have a freon leak you also are losing oil. Once you begin putting freon into the vacuum side of the compressor with the engine running ,, the clutch to the compressor should come on (if it wasn't on already) Be careful not to overcharge or you could blow the high pressure line apart.
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