2017 GMC Sierra 2500HD Coolant Capacity & Type

The 2017 GMC Sierra 2500HD coolant capacity varies by engine. This guide will provide details on coolant capacity, type, flush intervals, and common issues for your truck.

Quick Answer

• Total Cooling System Capacity (6.0L V8): Approximately 16.0 quarts (15.1 liters)
• Total Cooling System Capacity (6.6L Duramax Diesel): Approximately 24.5 quarts (23.2 liters)
• OEM Coolant Spec: DEX-COOL (Orange/Red, OAT, GM6277M)
• Mix Ratio: 50/50 Prediluted or Concentrate mixed with distilled water

Capacity by Engine Option

Flush Interval

For the 2017 GMC Sierra 2500HD, the recommended coolant flush interval using DEX-COOL is typically every 5 years or 150,000 miles, whichever comes first, under normal driving conditions. If your vehicle operates under severe duty conditions—such as frequent towing, hauling heavy loads, extreme temperatures, or extensive idling—it's wise to consider more frequent inspections and potentially shortening the flush interval. Regularly checking coolant levels and condition is always recommended.

How to Refill & Bleed

Refilling and bleeding the cooling system on your 2017 GMC Sierra 2500HD is a critical step to ensure proper cooling system operation and prevent air pockets. Always perform this procedure on a cool engine.

1. Drain the System: Locate and open the radiator drain petcock (or remove the lower radiator hose) to drain the old coolant into a suitable container. Remember to open the radiator cap to speed up draining.
2. Flush (Optional but Recommended): If performing a full flush, close the drain and refill 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. For a chemical flush, follow the product instructions.
3. Refill with New Coolant: Close the drain. Slowly fill the coolant reservoir (or radiator directly, depending on the system design) with the recommended DEX-COOL 50/50 mix. Filling slowly helps prevent air pockets.
4. Bleed the System:
   • 6.0L Vortec V8: Start the engine with the heater on high (fan speed low). As the engine warms up, the thermostat will open, and the coolant level in the reservoir may drop. Top off as needed. Some Vortec engines may have bleed screws near the thermostat housing or on the heater hoses; if present, open them until a steady stream of coolant emerges, then close. Run the engine at about 1500-2000 RPM for several minutes to help circulate coolant and expel air.
   • 6.6L Duramax Diesel: Ensure the coolant fill is at the "COLD" mark on the reservoir. Start the engine and let it idle until it reaches operating temperature. The system should self-bleed most air through the degas bottle/reservoir. You may need to squeeze the upper and lower radiator hoses several times to help move air. After the engine has cooled, recheck the coolant level and top off as necessary.
5. Final Check: After the engine has completely cooled, recheck the coolant level in the reservoir and top off to the "COLD" line if needed. Monitor the temperature gauge during subsequent drives for any signs of overheating.

Common Cooling System Issues

Owners of the 2017 GMC Sierra 2500HD, particularly those with higher mileage, may encounter some common cooling system issues:

• Water Pump Leaks: A relatively common wear item, especially on the 6.0L V8. Look for coolant puddles under the front of the vehicle or crusty pink/orange residue around the pump