2020 GMC Yukon Coolant Capacity & Type

The 2020 GMC Yukon cooling system capacity is approximately 16.7 quarts (15.8 liters) for the 5.3L V8 engine and 17.0 quarts (16.1 liters) for the 6.2L V8 engine.

Quick Answer

• Total Cooling System Capacity:
  • 5.3L V8: ~16.7 quarts (15.8 liters)
  • 6.2L V8: ~17.0 quarts (16.1 liters)
• OEM Coolant Spec: Dex-Cool (Orange, OAT - Organic Acid Technology), meeting GM Standard GM6277M.
• Mix Ratio: 50/50 Pre-mix or 50/50 concentrate with distilled water.

Capacity by Engine Option

Flush Interval

For the 2020 GMC Yukon, the recommended coolant flush interval is:

• Normal Duty: Every 5 years or 150,000 miles, whichever comes first.
• Severe Duty: If your vehicle is subjected to severe conditions (e.g., heavy towing, extreme temperatures, dusty environments), consider flushing every 3 years or 45,000 miles, possibly sooner depending on inspection.

Regular inspection of coolant levels and condition is always recommended, regardless of mileage or time.

How to Refill & Bleed

Refilling and bleeding the cooling system on a 2020 GMC Yukon is a crucial step to ensure proper cooling and prevent air pockets. Always perform this procedure on a cool engine.

1. Drain: Completely drain the old coolant from the radiator and engine block. Dispose of used coolant responsibly.
2. Close Drain Plugs: Securely close the radiator drain petcock and any engine block drain plugs.
3. Refill: Slowly add new 50/50 Dex-Cool coolant to the coolant reservoir until it reaches the "COLD FILL" mark.
4. Start Engine: Start the engine and let it run with the heater on high (fan speed low) to open the thermostat and circulate the coolant. Keep the reservoir cap off.
5. Burp Air: As the engine warms up, the coolant level may drop in the reservoir as air escapes. Continue to add coolant incrementally to maintain the "COLD FILL" level.
6. Squeeze Hoses (Optional but Recommended): Gently squeeze the upper and lower radiator hoses several times to help dislodge any trapped air bubbles.
7. Run to Temperature: Allow the engine to reach normal operating temperature. The radiator fans should cycle on and off.
8. Monitor Level: Once the engine is at operating temperature, install the reservoir cap. Drive the vehicle for a short period and then allow it to cool completely. Recheck the coolant level in the reservoir and top off if necessary.
9. Bleed Screws (If Applicable): The 2020 GMC Yukon typically relies on its integrated design to self-bleed. However, some engines may have a bleed screw located near the thermostat housing or on a cooling system hose. Consult your owner's manual or a service manual for the exact location if present. Slowly open the bleed screw until a steady stream of coolant, free of air bubbles, emerges, then close it.
10. Vacuum Fill (Professional Recommended): For the most thorough and effective bleed, especially after a major cooling system repair, a professional vacuum-fill tool is highly recommended. This method draws a vacuum on the system and then pulls in coolant, minimizing air pockets.

Common Cooling System Issues

For the 2020 GMC Yukon, and this generation of GM trucks/SUVs, some common cooling system issues to be aware of include:

• Water Pump Leaks: While not exclusively tied to the 2020 model year, water pump failures and leaks can occur prematurely. Listen for grinding noises or look for coolant puddles under the front of the vehicle.
• Coolant Reservoir Leaks/Cracks: The plastic coolant reservoir can sometimes develop cracks or leaks over time, leading to a slow loss of coolant.
• Thermostat Issues: A failing thermostat can cause the engine to overheat (stuck closed) or run too cool (stuck open), impacting fuel economy and engine performance.
• Radiator Leaks: Road debris or age can cause damage to the radiator, leading to leaks. Look for discolored areas on the radiator fins or coolant stains.
• Heater Core Issues: While less common than external leaks, a failing heater core can cause coolant odors inside the cabin, fogging of windows, or wet passenger floorboards.
• Dex-Cool Sludge (Older Generations): While significant improvements have been made, always ensure only genuine Dex-Cool is used and never mix with other coolant types, as this was historically a cause of sludging issues in older GM vehicles.

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