DIY Coolant Flush for 2019 Lexus ES 350 - Best Practices?

ClearTheCode admin answer:

Performing a coolant flush on your 2019 Lexus ES 350 is excellent preventative maintenance at 60,000 miles. Modern Lexus vehicles use a specific type of coolant, and proper procedure is key for a successful DIY job.

Here's a guide to best practices:

1. Coolant Type: Your 2019 ES 350 requires Toyota Super Long Life Coolant (SLLC), which is a pink/red, pre-mixed 50/50 ethylene glycol-based coolant. Do NOT use green or universal coolants, as they are incompatible and can cause corrosion or damage to your cooling system components. Always use distilled water if you're mixing concentrate, but SLLC is usually sold pre-mixed.
2. Safety First: Ensure the engine is completely cool before starting. Wear appropriate safety gear, including gloves and eye protection. Coolant is toxic, so prevent spills and dispose of old coolant responsibly at an approved recycling center.
3. Drain Procedure:
   • Locate the radiator drain plug at the bottom of the radiator (often on the driver's side). Place a large drain pan underneath.
   • Open the radiator cap to allow air in and facilitate draining.
   • Open the drain plug and let the coolant drain completely. Some models also have engine block drain plugs, but often a radiator drain and multiple drain/fill cycles are sufficient.
4. Flushing (Optional but Recommended): You can refill with distilled water, run the engine with the heater on until it reaches operating temperature (thermostat opens), then drain again. Repeat this process until the drained water runs clear. This helps remove more old coolant and contaminants.
5. Refill and Burp:
   • Close the radiator drain plug securely.
   • Slowly fill the radiator and coolant reservoir with the new Toyota SLLC. Fill the reservoir to the 'FULL' line.
   • Start the engine with the radiator cap off (or loosely on). Turn the heater to full hot and fan on low. This helps open the heater core valve to allow coolant to circulate.
   • As the engine warms up, you'll see air bubbles rise. Squeeze the upper and lower radiator hoses repeatedly to help dislodge air pockets (this is often called 'burping' the system).
   • Continue to add coolant as the level drops, keeping it topped off. Once the thermostat opens (you'll feel the upper radiator hose get hot), more bubbles will escape. Continue this for 15-20 minutes until no more bubbles appear and the coolant level stabilizes.
   • Install the radiator cap, ensuring it's tight.
6. Post-Flush Check: Drive the vehicle, then let it cool down completely. Recheck the coolant level in the reservoir and top off if necessary. Keep an eye on your temperature gauge for the next few drives.

When to See a Shop: If you're uncomfortable with any part of this process, or if you encounter issues like persistent air pockets, leaks, or overheating after the flush, it's best to consult a professional Lexus technician. They have vacuum-fill tools that can eliminate air pockets more effectively.