General consensous is to charge the 12oz cans with hose on top (gas charge). the cans are labelled that way as well...but, the cans with UV tracer say to charge upside down (hose down) which is a liquid charge. i thought this could damage a compressor by hitting it with a liquid slug on the suction side. i suppose the R134 with tracer needs to be loaded liquid so that the tracer gets carried in. Any suggestions or just follow the can instructions and hope for no liquid slug into the compressor?

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1972 450SL
1982 300D Turbo

It depends on how far the charge port is from the compressor. If it's at the accumulator, you could probably get away with liquid charging.

If you're still worried about slugging the compressor and that the can contents are stratified, you could always shake the can during charging.

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95 E320 Cabriolet, 159K