2019 Chevrolet Suburban Coolant Capacity & Type Guide

The 2019 Chevrolet Suburban holds between 16.7 and 18.1 quarts of coolant, depending on the engine option and whether the vehicle is equipped with a rear heating and cooling system. As an ASE-certified master technician, I regularly service these heavy-hauling family cruisers, and keeping the cooling system in top shape is critical for the longevity of GM's Gen V V8 engines.

Below is everything you need to know about the 2019 Chevy Suburban’s coolant requirements, flush intervals, and common issues.

Quick answer

When servicing your Suburban's cooling system, always ensure you are using the correct fluids and amounts to prevent overheating and internal engine damage. Here are the fast facts:

• Total cooling system capacity: 16.7 quarts (15.8 L) to 18.1 quarts (17.1 L). Suburbans with rear climate control hold the higher amount due to the extra heater core lines running to the back of the vehicle.
• OEM coolant spec: GM Dex-Cool. This is an OAT (Organic Acid Technology) coolant, universally recognized by its orange color. Look for coolant meeting GM specification GMW3420.
• Mix ratio: A 50/50 mixture of Dex-Cool concentrate and clean, drinkable water (distilled or deionized water is highly preferred to prevent mineral scale). Alternatively, you can purchase pre-mixed 50/50 Dex-Cool.

Capacity by engine option

The 2019 Suburban was primarily offered with the standard 5.3L V8, though the RST Performance Package introduced the 6.2L V8. Because almost all Suburbans are ordered with the rear HVAC system, most will take the higher capacity.

Note: Capacities are approximate. Always fill to the "Cold Fill" line on the surge tank and adjust after bleeding the system.

Flush interval

GM's Dex-Cool is designed to be a long-life coolant, but it isn't a "lifetime" fluid. Leaving depleted coolant in the system can lead to sludge formation and degraded gaskets.

• Normal Duty: Replace the coolant every 150,000 miles or 5 years, whichever comes first.
• Severe Duty: If you frequently tow heavy trailers, idle for long periods, or drive in extreme dusty/hot environments, I recommend flushing the system every 100,000 miles or 5 years. Time is just as important as mileage because the OAT anti-corrosion additives break down over the years.

How to refill & bleed

Because the Suburban features a large engine block and, usually, a rear heater core located all the way in the back of the cabin, air pockets can be notoriously stubborn. A vacuum-fill tool is highly recommended for this vehicle, but if you are doing it manually, follow these steps:

1. Drain the system: Make sure the engine is completely cold. Open the radiator petcock or remove the lower radiator hose to drain the old coolant.
2. Fill the surge tank: Close the drain and slowly pour your 50/50 Dex-Cool mixture into the pressurized surge tank (reservoir) until it reaches the cold fill line.
3. Run the engine: Leave the surge tank cap off. Start the engine and turn the front and rear heaters to their highest heat settings and lowest fan speeds. This opens the heater valves.
4. Bleed the air: Let the engine idle until it reaches normal operating temperature (you will feel the upper radiator hose get hot when the thermostat opens). You will see the coolant level drop as air burps out.
5. Top off and seal: Keep adding coolant to maintain the level at the cold fill line. Once the level stabilizes and hot air is blowing from both the front and rear vents, install the surge tank cap securely.
6. Test drive: Drive the vehicle, let it cool down completely, and check the surge tank level again. Top off as necessary.

Common cooling system issues

The 2019 Suburban is part of the K2XX generation (2015-2020), which is generally robust but has a few well-known cooling system quirks to watch out for:

• Leaking Radiator Side Tanks: The plastic end tanks on the OEM radiators are prone to stress cracks, particularly on the driver's side near the upper hose connection. If you smell sweet coolant but don't see a puddle, inspect the side seams of the radiator.
• Water Pump Weep Hole Leaks: The mechanical water pump on the 5.3L and 6.2L engines can fail internally. Check the weep hole on the underside of the pump behind the pulley; if you see orange crust or a drip, it's time for a new pump.
• Thermostat Failure (Code P0128): The thermostat can stick open, preventing the engine from reaching operating temperature in a timely manner. This will trigger a Check Engine Light and a P0128 code.
• Heater Hose Quick-Connects: The plastic quick-connect fittings for the heater hoses (especially at the firewall) become brittle with age and heat cycling, often snapping during unrelated engine work or simply leaking over time.

Keeping up with your coolant maintenance is the easiest way to prevent these issues from leaving you stranded. Find a trusted shop on Repairius.