Is it common to have two different coolants in coolant system

Hi, this is Bo, an auto expert on RepairPal's Car Genius team! It's not normal or recommended to have two different coolants in your 2011 Ford F-250 Super Duty's cooling system. Mixing different types of coolant—like red and yellow—can lead to chemical reactions that might cause corrosion, sludge buildup, or reduced cooling efficiency. Each coolant type has specific additives that work with certain engines, and mixing them can compromise those properties. I'd recommend taking the truck back to the shop and asking them to clarify what they used. If they mixed incompatible coolants, you might want to get a full system flush to avoid potential long-term damage. If you need any further advice or want help finding a trusted RepairPal shop in your area, please feel free to call us at 877-913-1554.