Coolant Reservoir Cap / Radiator Cap

A vehicle's engine consistently generates heat while running, and therefore must have a working cooling system in order to effectively divert heat away from your engine and prevent serious damage. Enter: the radiator. The radiator acts as a heat exchanger when the engine’s thermostat detects too high of a temperature, triggering the release of both water and coolant. While a coolant reservoir cap seems like a small component of this massively important system, it plays a vital role in maintaining the radiator's efficiency and overall performance.

The Importance of A Functioning Radiator Cap

With all the important cooling the radiator performs, a properly secured cap is essential in keeping your radiator engine cooled. You can potentially avoid a damaged radiator, or even prevent an overheated engine by replacing your faulty coolant reservoir cap.

Not only does the cover act as a seal from outside elements, it ensures pressure control within the entire cooling system. Not having a proper seal can compromise the system's ability to pressurize, especially considering that when the engine heats up, the coolant expands. The cap is designed to allow for pressure to build to a certain level and ensures it is released appropriately. Without a properly functioning cap, there could be devastating consequences to the engine, such as loss of power, piston damage, a blown head gasket, or cracked radiator.

Symptoms of a Faulty or Broken Radiator Cap

During a routine maintenance check, it is typical for a professional to inspect the cap, but things can certainly happen between inspections. There are signs to look for that may indicate the radiator cap is losing its integrity and while overheating signals an obvious issue, another easy indicator is leaking. If a puddle of coolant is left behind, it could mean that the cap is improperly releasing pressure, or the reservoir is overflowing. Another potential indicator is a collapsed radiator hose, which could be the result of the coolant not flowing properly.

Get the Right Part at the Right Price

If you find that the cap isn't sealing properly, a quality fix is easy. Simply set the Year Make and Model of your vehicle above and shop for radiator caps that are designed to meet your vehicle’s OEM specifications. AutoZone has the lowest prices on quality coolant reservoir caps and will ensure you get your part quickly when needed. Enjoy Free In-Store Pickup, Free Curbside Pickup & Free Next Day Delivery on eligible orders.

To learn more about your vehicle’s cooling system, check out some of these helpful articles for Trustworthy Advice:
- Car Cooling System Explained
- How to Replace a Radiator