2019 Toyota Highlander Coolant Capacity & Type

A 2019 Toyota Highlander typically holds between 7.7 and 9.0 quarts (7.3 to 8.5 liters) of coolant, depending on the engine. Properly maintaining your Highlander's cooling system is crucial for its longevity and performance. This guide covers everything you need to know about your vehicle's coolant capacity, type, maintenance, and common issues.

Quick Answer

• Total Cooling System Capacity: 7.7 - 9.0 quarts (7.3 - 8.5 liters)
• OEM Coolant Spec: Toyota Super Long Life Coolant (SLLC) - Pink, HOAT (Hybrid Organic Acid Technology)
• Mix Ratio: 50/50 pre-mixed coolant is recommended. If using concentrate, mix with distilled water at a 50/50 ratio.

Capacity by Engine Option

The 2019 Toyota Highlander was available with two primary engine options, each with a slightly different coolant capacity:

Always consult your owner's manual for the most accurate and specific capacity for your exact trim level and engine.

Flush Interval

Maintaining the correct coolant flush interval is vital for preventing corrosion and ensuring optimal cooling system performance.

• Normal Duty: The initial coolant change is recommended at 100,000 miles (160,000 km) or 120 months. Subsequent changes should occur every 50,000 miles (80,000 km) or 60 months.
• Severe Duty: If you frequently drive in extreme conditions (e.g., heavy towing, mountainous terrain, very hot climates, or dusty environments), it's wise to consider changing your coolant more frequently, possibly at half the normal interval.

Regularly checking your coolant level and condition between flushes is always a good practice.

How to Refill & Bleed

Refilling and bleeding your 2019 Toyota Highlander's cooling system properly is essential to prevent air pockets that can lead to overheating. While it's always best to have a professional perform this service, here are the general steps:

1. Safety First: Ensure the engine is completely cool before starting. Wear appropriate safety gear, including gloves and eye protection.
2. Drain System (if flushing): Open the radiator drain cock (petcock) at the bottom of the radiator and the engine block drain cocks (if applicable and accessible) to thoroughly drain the old coolant. Flush with distilled water if performing a full flush.
3. Close Drains: Once draining is complete, securely close all drain cocks.
4. Refill: Begin filling the radiator with the specified Toyota Super Long Life Coolant (SLLC) through the radiator fill neck. Fill slowly to allow air to escape.
5. Bleed Air:
   • With the radiator cap off, start the engine and let it run with the heater on full blast (to open the heater core valve).
   • Monitor the coolant level in the radiator and top off as needed. You may see bubbles as air escapes. Gently rev the engine a few times to help dislodge air.
   • Some Toyota models have a bleeder valve on the thermostat housing or radiator; if so, open this until a steady stream of coolant (without air bubbles) emerges, then close it.
   • Continue this process until no more air bubbles appear and the coolant level stabilizes. This can take 15-30 minutes.
6. Top Off & Test: Once the engine is warm and no more air is escaping, turn off the engine and allow it to cool completely. Recheck the coolant level in the radiator and the overflow reservoir, topping off as necessary. Drive the vehicle and monitor the temperature gauge.

Note on Vacuum Fill: For optimal air removal, especially after a full system drain, using a vacuum-fill tool is highly recommended. This method pulls a vacuum on the cooling system and then draws in new coolant, virtually eliminating air pockets.

Common Cooling System Issues for this Generation

While the 2019 Toyota Highlander is generally reliable, some common cooling system issues experienced by this generation (XU50, 2014-2019) or similar Toyota engines include:

• Water Pump Leaks: The water pump can sometimes develop leaks as the vehicle ages, often signaled by a pink crusty residue (from the coolant) around the pump housing or a noticeable coolant odor.
• Radiator Leaks: Radiators can develop leaks, particularly at the plastic end tanks. This might be visible as a wet spot under the vehicle or a drop in coolant level.
• Thermostat Failure: A failing thermostat can cause either continuous overheating (stuck closed) or the engine to not reach operating temperature (stuck open). Check engine lights related to engine temperature are common indicators.
• Radiator Cap Issues: A faulty radiator cap can lead to insufficient pressure in the system, causing coolant to boil at lower temperatures or allowing air to be drawn in, leading to overheating or poor heating performance.
• Coolant Hoses Degradation: Over time, coolant hoses can become brittle, crack, or soften, leading to leaks. Regular inspection of hoses for swelling, cracking, or softening is important.

Addressing these issues promptly can prevent more extensive and costly engine damage.

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