Have just removed the radiator to replace the ac and feel a little wobble or play in the belt pulley on the water pump. the car has 130.000 and does not leak but I am not sure if a slight wobble is normal.

A slight wobble or play is not normal. Recommend buying a reconditioned water pump from your local MB dealer before the current one fails and possibly causes the engine to overheat.

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Fred Hoelzle

Just to double-check, you're talking about the water pump itself and not the fan clutch. The clutch is more likely to wobble, and will probably fail soon with your miles. It is a much easier DIY than the pump, though.

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Prost!