2021 Ram 2500 Coolant Capacity & Type

The 2021 Ram 2500 holds approximately 16.5 to 19.5 quarts (15.6 to 18.4 liters) of coolant, depending on the engine.

Quick Answer

• Total Cooling System Capacity:
  • 6.4L HEMI V8: ~16.5 quarts (15.6 liters)
  • 6.7L Cummins Turbo Diesel: ~19.5 quarts (18.4 liters)
• OEM Coolant Spec: Mopar Antifreeze/Coolant 10 Year/150,000 Mile Formula OAT (Organic Additive Technology) in Purple. Meets Chrysler Material Standard MS-90032.
• Mix Ratio: Typically 50/50 prediluted, or mix concentrate with 50% distilled water.

Capacity by Engine Option

Flush Interval

• Normal Duty: Mopar recommends flushing the coolant every 10 years or 150,000 miles, whichever comes first.
• Severe Duty: For vehicles subjected to heavy towing, frequent off-road use, or extreme temperatures, it's advisable to inspect the coolant more frequently and consider replacing it sooner, potentially around 5 years or 75,000 miles.

How to Refill & Bleed

Refilling and bleeding the cooling system on a 2021 Ram 2500 is crucial to prevent air pockets, which can lead to overheating. Always perform this procedure on a cool engine.

1. Drain: With the engine cool, open the draincock on the bottom of the radiator and remove the radiator cap to allow the system to drain completely. For a full flush, you may need to repeat this process with distilled water until the draining water is clear.
2. Close Drain & Refill: Close the radiator draincock. Begin refilling the system slowly with the specified Mopar OAT coolant (50/50 mix). Fill the radiator and the coolant reservoir to the "COLD FILL" line.
3. Bleed Air (Gasoline Hemi): For the Hemi engine, there isn't a traditional bleed screw. Start the engine with the heater set to full hot and the fan on low. Allow the engine to reach operating temperature. As the thermostat opens, the coolant level in the reservoir may drop. Continue to top it off as needed. Squeeze the upper and lower radiator hoses several times to help release trapped air. Install the radiator cap once the engine is warm and stable.
4. Bleed Air (Diesel Cummins): The Cummins engine often benefits from a "vacuum fill" method to ensure all air is purged, especially after a complete drain. If you don't have access to a vacuum filler, follow the gasoline engine