2025 Ford F-350 Super Duty Coolant Capacity & Type

The 2025 Ford F-350 Super Duty holds approximately 24-28 quarts (22.7-26.5 liters) of coolant, depending on the engine and configuration.

Quick Answer

• Total Cooling System Capacity: 24-28 quarts (22.7-26.5 liters)
• OEM Coolant Spec: Orange, Organic Acid Technology (OAT), Ford Specification WSS-M97B51-A1 (Motorcraft Orange Antifreeze/Coolant Prediluted or Concentrate)
• Mix Ratio: 50/50 with distilled water for concentrate, or use pre-diluted.

Capacity by Engine Option

The 2025 Ford F-350 Super Duty offers several engine options, each with a slightly different cooling system capacity:

Flush Interval

Maintaining your F-350 Super Duty's cooling system is crucial for longevity and performance. Adhere to the following flush intervals:

• Normal Duty: Every 6 years or 100,000 miles, whichever comes first.
• Severe Duty: If your F-350 is used for heavy towing, hauling, off-road driving, or in extreme climates, consider flushing every 50,000 to 75,000 miles or every 3-4 years.

How to Refill & Bleed

Refilling and bleeding the cooling system on your 2025 F-350 Super Duty requires careful attention to ensure all air is removed, preventing overheating.

1. Safety First: Ensure the engine is cool before starting. Wear appropriate safety gear.
2. Drain Old Coolant: Locate the radiator drain plug and open it to drain the old coolant into a suitable container. You might also want to open drain plugs on the engine block if present.
3. Flush (Optional but Recommended): After draining, you can flush the system with distilled water until clear, then drain again.
4. Close Drains & Refill: Close all drain plugs. Slowly add the new 50/50 coolant mixture (or pre-diluted) to the radiator and the coolant reservoir up to the "MAX" or "COLD FILL" line.
5. Remove Air Pockets:
   • Start the engine with the heater on full blast (hot). This opens the heater core valve and allows coolant to flow through the entire system.
   • Allow the engine to reach operating temperature, monitoring the coolant level in the reservoir. Top off as needed.
   • Some F-350 models, particularly those with the Power Stroke diesel, may have dedicated bleed screws on the thermostat housing or other high points in the system. If present, open these slightly to allow trapped air to escape until a steady stream of coolant emerges, then close them.
   • Continuously squeeze the upper and lower radiator hoses to help dislodge air bubbles.
   • Run the engine until the thermostat opens (you'll feel the lower radiator hose get hot). This indicates coolant is circulating fully.
6. Final Check: Once the engine cools down, recheck the coolant level in the reservoir and top off if necessary. Monitor the level over the next few drive cycles.

For diesel models, a vacuum fill tool is often recommended by technicians to ensure a complete fill and prevent air pockets, as these systems can be more challenging to bleed manually.

Common Cooling System Issues for This Generation

While the 2025 Ford F-350 Super Duty is a robust truck, certain cooling system issues can emerge over its lifespan, similar to previous generations:

• Radiator Leaks: Over time, plastic end tanks can become brittle or seals can fail, leading to leaks. Corrosion can also occur in aluminum radiator cores.
• Water Pump Failure: The water pump is a wear item. Symptoms include leaks from the weep hole, whining noises, or engine overheating.
• Thermostat Issues: A stuck-open thermostat can cause the engine to run cool, reducing efficiency, while a stuck-closed thermostat can lead to rapid overheating.
• Hose Leaks/Failures: Radiator hoses and heater hoses can degrade, crack, or burst due to age, heat, and pressure.
• Coolant Contamination: Mixing incompatible coolant types can lead to detrimental chemical reactions, causing sludge formation, corrosion, and blockages within the cooling system.
• Degraded Coolant: Coolant loses its anticorrosive and heat transfer properties over time, emphasizing the importance of regular flush intervals.
• EGR Cooler Issues (Diesel): On Power Stroke diesel engines, the EGR cooler can be a point of failure, potentially leading to coolant consumption or mixing with exhaust gases.

Regular inspections and adherence to the recommended maintenance schedule can help prevent many of these issues.

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