The 2014 Ford Flex should use a Ford-approved, long-life coolant based on organic acid technology (OAT). The clearest option is Motorcraft Premium Engine Coolant in a 50/50 premixed formulation, which meets Ford’s specifications. If you choose an aftermarket coolant, ensure it is explicitly rated to Ford’s standard and used in a 50/50 mix with distilled water.
Coolant options for the 2014 Ford Flex
Ford designs the cooling system around an OAT, ethylene glycol–based long-life coolant. The simplest, most reliable choice is Motorcraft Premium Engine Coolant in a ready-to-use 50/50 premixed bottle. Aftermarket coolants may be acceptable if they explicitly meet Ford specification WSS-M97B51-A1 and are compatible with Ford engines.
- Motorcraft Premium Engine Coolant, 50/50 premixed (orange) — meets Ford WSS-M97B51-A1 specification.
- Any aftermarket coolant that explicitly meets Ford specification WSS-M97B51-A1 (OAT, ethylene glycol-based) and is labeled as Ford-approved.
Using a Ford-approved coolant ensures compatibility with the Flex’s cooling-system materials and seals. While color can vary between brands (often orange), the critical factor is meeting the Ford specification rather than color alone.
What to avoid
To prevent damage or cooling system problems, avoid coolants not rated for Ford’s specification or those that are not OAT-based. Using the wrong formula can lead to corrosion, gasket issues, or reduced cooling performance.
- Conventional green coolant not meeting Ford WSS-M97B51-A1 (non-OAT).
- GM Dex-Cool or other brands not certified as Ford-approved for this specification.
- Chemistries not ethylene glycol–based or not labeled for Ford’s WSS-M97B51-A1.
If you’re unsure whether a coolant meets Ford’s spec, consult the product label, the owner’s manual, or contact a Ford dealer or qualified mechanic before topping off or draining the system.
How to service or top off the cooling system
Proper procedure helps ensure a correct mixture and reliable cooling performance. The steps below assume you are using a Ford-approved coolant and either topping off or performing a full drain and fill.
- Ensure the engine is cool before opening any cooling-system components and remove the radiator cap only when safe.
- If topping off: pour Ford-approved coolant into the reservoir until it reaches the MAX mark. If using concentrate, mix with distilled water to a 50/50 ratio before pouring.
- If draining and refilling: drain the old coolant from the system, flush if needed, then refill with a 50/50 mix of Ford-approved coolant and distilled water.
- Bleed the cooling system according to Ford’s procedure to remove air pockets. This may involve running the engine with the heater on and monitoring the coolant level as air is purged.
- Check for leaks, recheck the level after the engine cools, and dispose of used coolant at an authorized recycling facility.
If you’re not comfortable performing a drain-and-fill or the bleeding procedure, it’s wise to have a professional technician handle the service to ensure the system is properly purged and filled.
Summary
For a 2014 Ford Flex, the recommended coolant is a Ford-approved long-life, ethylene glycol–based coolant that meets Ford specification WSS-M97B51-A1. The most straightforward option is Motorcraft Premium Engine Coolant, 50/50 premixed. Always verify compatibility on the product label and avoid non-Ford or non-OAT formulas. When in doubt, consult the owner’s manual or a Ford service professional to confirm the exact specification and service procedure.