Whats wrong with yours now? Mine, 97 E420, had a small leak behind the pulley. Threw fluid over into the left front fender area behind the headlight assembly. Someone told me about replacing just the seal behind the pulley. It was really a simple "diy". The parts, seal kit from MB and fluid, were only about $20.00. Pulled the pulley off, took the pump mechanism out of the pump housing, pushed the old brittle seal out, pushed the new one in, replaced the pump into the housing and filled up the reservoir. The total job took only about 1 1/2 hours.........and I fly jets. No master tech here just used my head alittle......which gave me a headache afterwards!
Jeff