2021 Toyota Tundra Coolant Capacity & Type

The 2021 Toyota Tundra holds approximately 15.3-16.5 quarts (14.5-15.6 Liters) of coolant in its cooling system, depending on the engine and configuration. This guide will provide you with all the essential information regarding your Tundra's coolant.

Quick Answer

• Total Cooling System Capacity: 15.3-16.5 quarts (14.5-15.6 Liters)
• OEM Coolant Spec: Toyota Super Long Life Coolant (SLLC), pink, Pre-diluted 50/50, Phosphate Organic Acid Technology (POAT).
• Mix Ratio: 50/50 Pre-diluted (do not add water).

Capacity by Engine Option

The 2021 Toyota Tundra was primarily offered with the 5.7L V8 engine. The cooling system capacity for this engine is approximately:

• 5.7L V8: 15.3-16.5 quarts (14.5-15.6 Liters)

Flush Interval

Maintaining the correct coolant flush interval is crucial for the longevity of your cooling system components and overall engine health. Toyota recommends the following for Super Long Life Coolant (SLLC):

• Normal Duty: The first replacement is recommended at 100,000 miles (160,000 km) or 120 months (10 years), whichever comes first. After the initial replacement, subsequent replacements are recommended every 50,000 miles (80,000 km) or 60 months (5 years).
• Severe Duty: If your vehicle is subjected to severe operating conditions (e.g., heavy towing, extreme temperatures, dusty conditions), it's wise to consider shortening the flush interval. Consult your owner's manual for specific severe duty recommendations, but generally, a 30% reduction in the normal interval is a good guideline.

How to Refill & Bleed

Properly refilling and bleeding the cooling system is critical 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 drain cock on the bottom of the radiator and remove the radiator cap to allow the system to drain completely. Some models may also have engine block drain plugs.
2. Close Drain: Once drained, close the radiator drain cock securely.
3. Refill: Slowly fill the radiator with the recommended Toyota Super Long Life Coolant (SLLC) until it reaches the top. Fill the coolant reservoir to the "FULL" mark.
4. Bleed Air:
   • Start the engine with the radiator cap off (or loosely placed on top if splashing is an issue) and the heater on full hot (this opens the heater core valve to allow coolant circulation).
   • Allow the engine to warm up to operating temperature. As the thermostat opens, the coolant level in the radiator will likely drop significantly. Continue to add coolant to keep the radiator full.
   • Rev the engine gently a few times (to about 2,500-3,000 RPM) to help dislodge any trapped air.
   • Look for air bubbles coming out of the radiator fill neck. Continue this process until no more bubbles appear.
   • Once the fan kicks on and the coolant level stabilizes with no more bubbles, install the radiator cap.
5. Check Reservoir: Drive the vehicle for a day or two and monitor the coolant level in the reservoir. Top it off to the "FULL" line as needed. The system will self-bleed any remaining small air pockets into the reservoir.

Special Note: The 2021 Toyota Tundra's 5.7L system generally self-bleeds well. No specific bleed screws are typically present on the engine for this model year, unlike some other vehicles. A vacuum filler can expedite the process and ensure a complete fill, especially if you're uncomfortable with the manual bleeding procedure.

Common Cooling System Issues for this Generation

While the 2021 Toyota Tundra is generally reliable, some common cooling system issues that owners occasionally encounter (or have been noted in this generation/engine) include:

• Water Pump Leaks: The water pump can be a wear item, and signs of a failing pump include coolant leaks around the pump shaft or pulley, whining noises, or engine overheating.
• Radiator Leaks: Radiators can develop leaks over time due to corrosion, stone chips, or plastic end tank failures. Keep an eye out for pink coolant stains under the front of the vehicle.
• Thermostat Failure: A failing thermostat can cause the engine to either run too hot (stuck closed) or too cold (stuck open), leading to inefficient operation or overheating. Symptoms include erratic temperature gauge readings or no heat from the vents.
• Hose Leaks/Cracks: Coolant hoses can degrade and crack over time, leading to leaks. Regularly inspect hoses for bulges, cracks, or softness.
• Coolant Reservoir Cracks: The plastic coolant reservoir can sometimes crack, especially with age and exposure to temperature extremes, leading to a slow coolant loss.

Regular maintenance and using the specified Toyota Super Long Life Coolant are your best defenses against these common issues.

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