You system must haev been serviced before and they inject dye in it to see where the leaks are. Looks to me that its possible that nut is not tight. Tighten the nut and wipe it clean to see if the leak stops.

If the leak stops, and the a/c still works good, then you are OK. If the leak doesn't stop, then the a/c will eventually stop cooling. If the a/c doesn't cool enough, its leaked too much already and you need to recharge the system. Meanwhile tighten the nut to see if you can stop the leak.

-=>Raja.

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1983 MB 190E, bought from Germany and shipped to the US in 1986.