2021 Chevrolet Suburban Coolant Capacity & Type

The 2021 Chevrolet Suburban cooling system holds approximately 16.3 quarts (15.5 liters) of coolant.

Quick Answer

• Total Cooling System Capacity: 16.3 quarts (15.5 liters)
• OEM Coolant Specification: Dex-Cool (Orange/Reddish-Orange, OAT, GM P/N 9986153 or equivalent)
• Mix Ratio: 50/50 Prediluted or Concentrate mixed with distilled water

Capacity by Engine Option

The 2021 Chevrolet Suburban was offered with several engine options, and their cooling system capacities are as follows:

Flush Interval

Maintaining your Suburban's cooling system properly is crucial for its longevity. General Motors recommends the following coolant flush intervals:

• Normal Duty: Every 5 years or 150,000 miles, whichever comes first.
• Severe Duty: If you frequently tow, operate in extreme temperatures, or drive in dusty conditions, it's wise to consider flushing the coolant more frequently, possibly every 3 years or 45,000 miles.

Always refer to your owner's manual for the most accurate and up-to-date maintenance schedule.

How to Refill & Bleed

Refilling and bleeding your 2021 Chevrolet Suburban's cooling system is an important process to ensure all air is removed, preventing overheating. Here's a general procedure:

1. Safety First: Ensure the engine is completely cool before starting. Wear appropriate safety gear, including gloves and eye protection.
2. Drain Old Coolant: Place a drain pan under the radiator drain petcock (or lower radiator hose) and open it to drain the old coolant. For a complete flush, you may want to drain the engine block as well, if equipped with drain plugs.
3. Flush (Optional but Recommended): If performing a full flush, close the drain and fill the system with distilled water. Run the engine with the heater on high until it reaches operating temperature, then drain. Repeat until the drained water is clear.
4. Refill: Close the radiator drain and fill the coolant reservoir with the specified Dex-Cool 50/50 mixture. Fill slowly to help minimize air pockets.
5. Bleed the System:
   • Start the engine with the radiator cap off (or reservoir cap, depending on design). Keep the heater on high.
   • As the engine warms up, the thermostat will open, and coolant will begin to circulate. You may see air bubbles escaping.
   • Maintain the coolant level in the reservoir by adding more as needed.
   • Some Suburbans may have a dedicated bleed screw on the thermostat housing or an upper hose. If present, open this screw slowly to release trapped air until a steady stream of coolant emerges, then close it.
   • Once the engine reaches operating temperature and no more air bubbles appear, install the radiator/reservoir cap.
6. Final Check: Drive the vehicle and monitor the temperature gauge. After the engine cools down, recheck the coolant level in the reservoir and top off if necessary.

Note: A vacuum-fill tool is often used by professionals for a more thorough and efficient air removal process, especially on modern vehicles that can be challenging to bleed manually.

Common Cooling System Issues for this Generation

While the 2021 Chevrolet Suburban builds on a solid platform, like any vehicle, its cooling system can experience specific issues. For this generation (GMT T1XX, 2021-Present), some common concerns might include:

• Thermostat Failure: Thermostats can fail by sticking open (leading to slow warm-up or not reaching operating temperature) or sticking closed (leading to overheating). Symptoms include fluctuating temperature gauges or the engine running hotter/colder than normal.
• Water Pump Leaks: The water pump is a wear item, and its internal seals can eventually degrade, leading to coolant leaks. Watch for puddles under the vehicle or a noticeable drop in coolant level.
• Radiator Leaks: Road debris or age can cause damage to the radiator fins and tubes, leading to leaks. Inspect the front of the radiator for signs of fluid or corrosion.
• Hose Leaks/Degradation: Over time, coolant hoses can become brittle, crack, or soften, leading to leaks. Regularly inspect hoses for bulges, cracks, or soft spots.
• Coolant Expansion Tank Issues: The plastic expansion tank can develop cracks or leaks over time, particularly around hose connections or seams. A visible leak or persistent low coolant level despite no other apparent leaks can indicate an issue with the tank.

Find a trusted shop on Repairius.