GM Genuine Parts Engine Coolant Reservoir Hoses are designed, engineered, and tested to rigorous standards, and are backed by General Motors. These hoses direct any excess or overflowing coolant within the cooling system to the reservoir. GM Genuine Parts are the true OE parts installed during the production of or validated by General Motors for GM vehicles. Some GM Genuine Parts may have formerly appeared as ACDelco GM Original Equipment (OE). WARNING: Cancer and Reproductive Harm