IYAAYAS, if you're lucky the A/C compressor is bad and needs to be replaced. If the evaporator leaks the entire dashboard needs to be removed and the evaporator replaced ... to the tune of $4,000.

With the custom drive belt configuration in your 1995 E320 there may be less contact area on the A/C compressor pulley causing it to squeal. You may want to consider installing a non-functioning air pump that restores the original drive belt length and configuration.

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Fred Hoelzle