"Burping" the cooling system in your Toyota refers to bleeding the cooling system and is necessary if air has entered the system. Air in the cooling system causes hot spots and subsequently overheating and serious engine damage. To prevent serious engine damage, take a few minutes to bleed the cooling system of air. Bleeding the cooling system in your Toyota is very simple and best of all doesn't require any tools.
Allow the engine to cool down to ambient temperature.
Open the radiator cap.
Turn the engine on and turn the heat to max. Turning the heat to max allows the radiator fluid to circulate through the cooling system to ensure that all air pockets are eliminated from the system.
Rev the engine to 2,000 RPMs and hold for approximately 10 to 15 seconds and repeat two to three times. This will allow the radiator fluid to circulate throughout the whole system and ensure that all air pockets exit the radiator.
Gently squeeze the upper radiator hose approximately 6 to 12 inches from the radiator cap. Squeeze about five times. This will bring more air pockets up and out of the radiator and will ensure that the engine does not overheat.
Wear safety glasses to protect your eyes and gloves to avoid serious skin burns.