2021 Ram 1500 Coolant Capacity & Type

The 2021 Ram 1500 cooling system typically holds between 13-16 quarts (12.3-15.1 liters) of coolant, depending on the engine and specific configuration.

Quick Answer

• Total Cooling System Capacity: 13-16 quarts (12.3-15.1 liters)
• OEM Coolant Spec: Mopar Antifreeze/Engine Coolant 10 Year/150,000 Mile (Pink/Purple, OAT, FCA MS-90032 or MS-12106)
• Mix Ratio: 50/50 Pre-mixed or concentrate to be mixed with distilled water

Capacity by Engine Option

Note: These capacities are approximate and may vary slightly based on specific vehicle options and cooling system variations. Always consult your owner's manual for the most accurate information.

Flush Interval

Maintaining your cooling system with regular flushes is crucial for the longevity of your 2021 Ram 1500. The recommended intervals are:

• Normal Duty: Every 10 years or 150,000 miles, whichever comes first.
• Severe Duty (e.g., heavy towing, extreme temperatures, off-road use): More frequent inspections are recommended, and replacement may be advisable as early as 5 years or 75,000 miles, depending on the condition of the coolant.

Always inspect your coolant regularly for color, clarity, and debris. If it appears murky, discolored, or contains particles, it's time for a flush, regardless of mileage or age.

How to Refill & Bleed

Properly refilling and bleeding your 2021 Ram 1500's cooling system is essential to prevent air pockets, which can lead to overheating. Here's a general procedure:

1. Safety First: Ensure the engine is completely cool before attempting to open the radiator cap or drain the system.
2. Drain (if flushing): Locate and open the radiator drain cock (petcock) at the bottom of the radiator. Some models may also have engine block drain plugs. Catch all old coolant in an appropriate container for disposal.
3. Flush (Optional): If performing a full flush, close the drain cock, fill with distilled water (and a cooling system cleaner if desired), run the engine to operating temperature with the heater on high, then drain again. Repeat until the water runs clear. Never use tap water.
4. Refill: Close all drain points. Slowly add the specified Mopar OAT coolant (50/50 mix with distilled water if using concentrate) to the coolant reservoir/radiator. Fill to the "COLD FILL" line.
5. Bleed the System: This is critical. Start the engine with the heater on high and the radiator cap off. As the engine warms up, the thermostat will open, and air bubbles will begin to escape. Continue to add coolant as the level drops in the reservoir. On some 2021 Ram 1500 models, there may be a dedicated bleed screw located on a thermostat housing or coolant pipe – open this slightly until a steady stream of coolant emerges, then close. Many modern systems are designed to self-bleed, but continuous monitoring and topping off are necessary.
6. Squeeze Hoses: Gently squeeze the upper and lower radiator hoses to help dislodge trapped air bubbles.
7. Drive Cycle & Recheck: Drive the truck for a short period, allowing it to reach full operating temperature. After the engine has cooled completely, recheck the coolant level in the reservoir and top off as needed. Repeat this process over the next few drive cycles.

A vacuum-fill tool is highly recommended for a thorough and efficient refill, especially on systems prone to air pockets.

Common Cooling System Issues for This Generation

The 2021 Ram 1500, while robust, can experience a few common cooling system-related issues that owners should be aware of:

• Water Pump Leaks: Particularly on the 3.6L Pentastar engine, the water pump can be a known failure point, often exhibiting a weep or leak from the weep hole.
• Thermostat Housing Leaks: The plastic thermostat housing, especially on the Pentastar V6, can be prone to cracking or developing leaks over time.
• Radiator Leaks: Over time, radiators can develop leaks, often at the plastic end tanks where they meet the aluminum core.
• EGR Cooler Issues (EcoDiesel): The 3.0L EcoDiesel engine can have issues with the EGR cooler failing, leading to coolant consumption or mixing with exhaust gases.
• Coolant Reservoir Cracks: The plastic coolant expansion tank can sometimes develop hairline cracks, leading to slow coolant loss.
• Sensor Malfunctions: Coolant temperature sensors or level sensors can occasionally fail, leading to incorrect readings or warning lights.

Regular inspections and adherence to the recommended coolant flush intervals can help mitigate many of these issues.

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