2020 Chevrolet Suburban Coolant Capacity & Type

The 2020 Chevrolet Suburban holds approximately 16.7 quarts (15.8 liters) of coolant in its cooling system.

Quick Answer

• Total Cooling System Capacity: 16.7 quarts (15.8 liters)
• OEM Coolant Spec: DEX-COOL (Orange/Red, OAT, GM Standard GM6277M)
• Mix Ratio: 50/50 Pre-diluted or 50/50 concentrate with distilled water

Capacity by Engine Option

The 2020 Chevrolet Suburban was offered with two engine options, both having similar cooling system capacities.

Flush Interval

Maintaining the correct coolant and flush interval is crucial for the longevity of your Suburban's cooling system.

• Normal Duty: Replace every 5 years or 150,000 miles, whichever comes first.
• Severe Duty: If your vehicle is regularly subjected to heavy towing, extreme temperatures, or dusty conditions, consider shortening the flush interval to every 3 years or 45,000 miles.

Regularly checking your coolant level and condition is also recommended to catch any issues early.

How to Refill & Bleed

Refilling and bleeding the cooling system correctly after a flush or repair is vital to prevent air pockets, which can lead to overheating.

1. Drain System: With the engine cool, open the petcock on the bottom of the radiator and remove the radiator cap to allow the system to drain completely. Some models may also have drain plugs on the engine block.
2. Close Drains: Once drained, close the radiator petcock and any engine block drain plugs.
3. Refill: Slowly fill the system through the radiator fill neck (or surge tank, if equipped) with the specified DEX-COOL 50/50 mixture. Be patient, as this allows air to escape.
4. Burp System: Start the engine with the heater on full blast (this opens the heater core valve). Allow the engine to reach operating temperature. As the engine warms up, the thermostat will open, and coolant will begin to circulate. Watch for the coolant level to drop in the reservoir/radiator and top it off as needed. Squeeze the upper and lower radiator hoses to help dislodge air bubbles.
5. Check for Air Pockets: If your Suburban has a bleed screw (often located on or near the thermostat housing), open it carefully while the engine is running to release trapped air until a steady stream of coolant emerges. Note: The 2020 Suburban typically relies on the surge tank and system design to self-bleed well, making a dedicated bleed screw less common.
6. Final Check: Once the engine is at operating temperature and no more air bubbles appear, replace the radiator cap. Drive the vehicle and monitor the temperature gauge. After the engine has cooled completely, recheck the coolant level and top off if necessary.

Common Cooling System Issues for this Generation

Owners of the 2020 Chevrolet Suburban (and the broader GMT K2XX platform) may encounter some common cooling system issues:

• Water Pump Leaks: This is a relatively common issue across many GM vehicles of this era. Keep an eye out for coolant drips around the front of the engine, particularly under the water pump pulley.
• Coolant Expansion Tank Leaks: The plastic expansion tank can develop cracks over time, leading to slow coolant leaks. Inspect the tank for visible cracks or dampness.
• Thermostat Housing Leaks: The thermostat housing, often made of plastic, can warp or crack, causing coolant to leak. Look for signs of coolant around the thermostat assembly.
• Radiator Leaks: While less common in newer vehicles, radiators can still develop leaks from road debris impact or general wear and tear, especially around the plastic end tanks.
• Heater Core Issues: Although not directly a capacity issue, a failing heater core (often indicated by a sweet smell inside the cabin or persistent fogging of windows) can be related to coolant quality or system issues. While less common in a 2020 model, it's worth noting for the general platform.
• Dex-Cool Sludge (Historical Note): While largely resolved with modern DEX-COOL formulations and proper maintenance, older generations of DEX-COOL had a reputation for forming sludge when mixed with incompatible coolants or if maintenance was neglected. Sticking strictly to DEX-COOL and proper flush intervals prevents this.

Ignoring cooling system problems can lead to severe engine damage, including overheating and head gasket failure. Regular inspections and adherence to maintenance schedules are vital.

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