BMW 17128602602 Reservoir Hose Assembly

The BMW 17128602602 reservoir hose serves as the expansion tank line connecting the coolant expansion tank to the auxiliary water pump and engine thermostat. Constructed from EPDM (ethylene propylene diene monomer) rubber, the hose withstands thermal cycling and system pressure in BMW B48 and B46A 2.0L turbocharged engines. The assembly features quick-connect couplings for secure attachment to the expansion tank and engine cooling circuit. Designed as a direct OEM replacement, it maintains factory coolant flow dynamics and sealing integrity. This component fits BMW G-chassis platforms including G11/G12 7 Series, G30/G31 5 Series, G32 6 Series GT, and G38 7 Series LCI models produced from 2017 through 2023. The hose manages coolant overflow and maintains optimal system pressure during engine warm-up and cool-down cycles. Material composition meets BMW specifications for resistance to coolant additives, ozone, and under-hood temperature extremes.