why is my Toyota Highlander XU70 (2020-Present) losing coolant with no leaks

Solution

1. Preparation

• Gather necessary tools and parts.
• Ensure the engine is cool before starting work.
• Disconnect the battery to avoid electrical issues.

2. Replace Faulty Components

A. Thermostat Replacement

1. Drain the coolant from the radiator and engine block.
2. Remove the thermostat housing bolts using a socket set.
3. Remove the old thermostat and gasket.
4. Install the new thermostat and gasket.
5. Torque the housing bolts to the manufacturer's specifications (typically 15-20 ft-lbs).

B. Water Pump Replacement (if faulty)

1. Remove any necessary components (serpentine belt, timing cover, etc.) to access the water pump.
2. Disconnect the water pump hoses and remove the mounting bolts.
3. Replace the old water pump with a new one, ensuring the gasket surface is clean.
4. Torque the mounting bolts to the manufacturer's specifications.

3. Refill and Bleed Cooling System

1. Refill the cooling system with manufacturer-recommended coolant.
2. Start the engine and allow it to reach operating temperature.
3. With the heater on, open the bleed valve (if equipped) to remove air from the system.
4. Monitor the coolant level and top off as necessary.