This OE-quality radiator expansion bottle cap is designed to release pressure at 1.2 BAR, protecting the cooling system during extreme operating conditions. Cooling systems are designed to run under pressure, allowing coolant to circulate efficiently and maintain stable engine temperatures.

A worn or faulty cap can prevent the system from reaching the correct pressure, often leading to overheating or fluctuating temperatures. Replacing the cap is a quick, inexpensive first step whenever overheating is suspected, ensuring proper system function and safeguarding engine health.