RepairPal Certified shops can diagnose and repair your 1990 Mercedes-Benz 300SEL. They provide transparent pricing with a minimum 12-month or 12,000-mile warranty on repairs and services.
"VALVE REPLACED - VALVE STILL LEAKS" then you got ea defective VALVE! --......--OR the part was replaced only for a 'code' and did not have complete diagnosis performed.?