Connecting the upper radiator to the top fitting on the engine (next to the oil filter housing). Over time, rubber hoses can become hard, with the internal walls covered in sediment and the plastic fittings turning brittle or the internal o-rings simply leaking. A must replace hose for any owner of a 135i or 335i looking to preventively maintain or restore their cooling system. We've found these Febi hoses to be great quality, which is manufactured by an original equipment supplier.

Part Number: 17127540127
Rein Part Number: CHR0405R