BMW z3 (99-02) Water Hose Expansion Tank to Radiator engine coolant line pipe Water Hose Expansion Tank to Radiator Brand NEW part with full 1 year warranty. BMW part# 11 53 1 436 122, note the mid-year splits. Recently made by CONTITECH (OEM), not been lying around. Please NOTE the mid-year split on PRODUCTION date. Not sure about your car? email us your VIN to confirm.