How to Seal a Leaking Radiator Cap How to Seal a Leaking Radiator Cap

What You'll Need
Black Pepper

radiator cap is crucial to keeping your car cool. If your car overheats, it could lead to to other problems that can be either expensive or impossible to fix. A leak in the radiator cap should be addressed immediately. Here are the steps to take to fix a leak in the radiator cap.

Step 1 – Identifying a Leak

You'll know you have a leaking radiator cap if you find a  green liquid leaking from underneath your car. No matter how little liquid is leaking, you need to fix it now because it will only get worse.

Step 2 – Let Car Cool Off

Allow your car to cool off before you attempt any work on the radiator. Give your car at least a half of an hour before you even lift the hood. Whenever you take the radiator cap off you will first need to use gloves and goggles just in case it is still hot. You will find that if your car is sitting out in the sun that there may be problems with it cooling off quickly. You can get severe burns from the steam when you lift up the cap if you are not careful. Look for a release valve on the radiator cap so that any excess steam and pressure will have a chance to escape.

Step 3 – Add Pepper

Get a single ounce of coarse black pepper. Add it to the water in your radiator. You will then need to top up the rest of the radiator fluid with whichever coolant you prefer to use. Pepper is known to stop leaks. Once you have done this you will need to get your radiator cap back into place and press down on the safety release valve.

Step 4 – Test

Once you have added the pepper drive your car around for about ten minutes and then allow your car to sit. Look for any green liquid. Add more pepper if you are still having problems with leaks.

Step 5 – When All Else Fails

You may need to end up replacing the radiator cap if you cannot find a good way to stop the leak. Over time, you will need to do it eventually as all leaks will eventually lead to bigger leaks. Radiator caps can be found at any nearby auto parts store and are typically not very expensive.

Step 6 – Consult Professional

If the leak is especially bad and you do not wish to replace the radiator cap, then you may want to take your car to a professional. Since this is a fairly simple, common fix, you should be able to find a mechanic who will do it for a very reasonable price.

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