I would never introduce a wet lubricant. They are known to retain dust and grit which will accelerate wear. Powered graphite will make the nastiest lock smooth as silk, and when used from new, will make a lock last forever.

If your lock already is contaminated with dirt or brass key shavings, I would use only compressed air to blow it out, not any liquid product.

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1998 E300 turbodiesel

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