Section 9 (Anti-Lock/Traction Control): Servicing
WARNING: This page is about a different car, the 1996 Mercedes-Benz E320, 1996 Mercedes-Benz E300, 1995 Mercedes-Benz E420, 1995 Mercedes-Benz E320, and 1995 Mercedes-Benz E300. However, it is still accessible from the selected car via links, so may be relevant.
Manufacturer recommends replacing brake fluid every 2 years, preferably in spring.