Radiator Coolant Overflow Tank Reservoir Mack & Volvo (2008-2018)Direct Fit Radiator Coolant Overflow Tank Reservoir for 2008 2018 Volvo, Mack V Series What it Does: Replaces a cracked or leaking factory coolant reservoir to restore proper heavy duty engine thermal management and prevent catastrophic coolant loss on the road. The Stock V Series Coolant Reservoir Weakness Heavy duty trucks like the Volvo VNL and Mack Pinnacle operate under extreme thermal loads and constant low frequency vibrations from large