Mercedes w203 C-230 Expansion Tank Hose to Engine GENUINE oem Expansion Tank Hose From Expansion Tank To Engine Genuine Mercedes part, recently made: not been lying around. Mercedes part# 203 501 00 25, check fit below. Fits: 203.040: (2003-2005): c230 sedan Fits: 203.740: (2003-2005): c230 coupe