2018 Ford F-350 Super Duty Coolant Capacity & Type

The 2018 Ford F-350 Super Duty can hold between 20.8 and 38.8 quarts (19.7 to 36.7 liters) of coolant depending on the engine and equipment.

Quick Answer

• Total Cooling System Capacity: 20.8 to 38.8 quarts (19.7 to 36.7 liters) - see table below for engine-specific capacities.
• OEM Coolant Specification: Ford Motorcraft Orange Antifreeze/Coolant Prediluted (VC-3-D or VC-3-D2). This is a Phosphate-Organic Acid Technology (P-OAT) coolant. The Ford specification is WSS-M97B44-D2.
• Mix Ratio: 50/50 mix of coolant and distilled water. It is recommended to use a pre-mixed, ready-to-use formula to ensure the correct ratio.

Capacity by Engine Option

The 2018 F-350 was available with two different engines, which have different cooling system capacities. Auxiliary heaters also affect the total volume.

Flush Interval

Following the factory-recommended service intervals is crucial for maintaining the health of your cooling system.

• Normal Service: The initial coolant flush should be performed at 200,000 miles or 10 years. After the initial service, the interval is every 50,000 miles or 3 years.
• Severe Duty: For vehicles that see heavy towing, extensive idling, or operate in extreme temperatures, it's recommended to shorten the interval. The initial change is recommended at 120,000 miles or 6 years, with subsequent changes every 45,000 miles or 3 years.

How to Refill & Bleed

Properly refilling and bleeding the cooling system is essential to prevent air pockets, which can cause overheating.

1. Mix Coolant: If using concentrate, mix it 50/50 with distilled water in a clean bucket. Using a pre-diluted formula is recommended.
2. Slow Fill: Add the new coolant to the degas bottle (expansion tank) slowly. Do not fill the radiator directly.
3. Check the Level: Fill the system until the coolant level is between the "MIN" and "MAX" marks on the degas bottle.
4. Run the Engine: With the heater on the highest temperature and fan setting, start the engine and let it run for several minutes to warm up and circulate the coolant. This will help purge air from the system.
5. Monitor Level: As the engine runs, the coolant level in the degas bottle will likely drop as air is purged. Continue to add coolant as needed to maintain the level between the MIN/MAX marks.
6. Use a Spill-Free Funnel: For best results, use a spill-free funnel that attaches to the degas bottle. This tool allows you to overfill the funnel, using the weight of the extra coolant to force air out of the system more effectively.

Common Cooling System Issues

The 2017-2019 generation of Super Duty trucks is generally reliable, but some issues can arise, particularly with the complex 6.7L Power Stroke diesel engine.

• Degas Bottle (Expansion Tank) Leaks: The plastic degas bottle can develop hairline cracks over time, leading to slow coolant loss and a drop in pressure.
• EGR Cooler Issues: The EGR (Exhaust Gas Recirculation) cooler can become clogged or fail, potentially leading to coolant loss or more significant engine issues. This is more common on higher-mileage trucks.
• Radiator Leaks: The primary radiator on the 6.7L Power Stroke has been known to develop leaks, especially at the end tanks where the plastic is crimped to the aluminum core.
• Water Pump Failure: While not rampant, water pump failure is a possibility on any vehicle. Signs include a visible leak from the pump housing or a whining/grinding noise from the front of the engine.

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