A coolant leak may develop form the Radiator due to degradation of its plastic components. Replacement of the failed radiator will be necessary.Google+
Car Problem Reports
Mercedes-Benz 600SEL Radiators Break Due to Degradation of the Plastic Tanks and Fittings
Mercedes-Benz 600SEL Problem
Average Mileage: 135,000 mi (135,000 mi - 135,000 mi)
radiator leaks could not be stopped-replaced
Visitor, 1993 Mercedes-Benz 600SEL, 135,000 mi
radiator replaced at 135,000 miles due to a hole that could not be healed.