BC3Z-8590-F OE Coolant Overflow Reservoir Lower Hose To Pump Seal, 2011, 2012, 2013, 2014, 2015, 2016, 2017, 2018, 2019 Ford 6.7 Powerstroke

This o-ring is for the lower hose from the coolant tank to the pump where the hose connects to the pump.