Most radiators eventually leak. The problem is that small pin hole sized leaks are frequently hard to diagnose, and the leaks can be difficult to find.
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Some of these small leaks will only leak when they under pressure when the car is hot. Larger leaks are easier to find, but can be much more painful to repair. Repairing a car radiator can range from a small quick temporary fix to a complete radiator replacement.
If your radiator has a large crack or multiple leaks, replacement is almost always the better option.
Unless you can do the welding yourself, the labor costs of having major radiator repairs done can easily eclipse the price of a new radiator. The good news is that radiators are often not hard to replace as a do-it-yourself project. Usually, all that is required is to remove any parts that are in the way of lifting the radiator from the car along with the upper and lower hoses.
Cars with an automatic transmission may have cooling lines going into the radiator. Once the radiator is clear, you need to remove a few bolts at the top and maybe at the bottom and lift it out. Some radiators do not have any lower fasteners because they sit in a track or have rubber feet that go in holes to secure the lower portion in place.
Small leaks can be remedied temporarily in an emergency.
If you have purchased coolant that has stop leak properties, you may just need to add coolant and drive the car a couple of miles to let the coolant do the work for you. However, if you have a leak, there is a good chance that this means either the leak is too large, or you do not have stop leak coolant. There are two simple old remedies for small radiator leaks that work as long as the car is running with pressure on the coolant. Often when you shut off the engine, these temporary fixes let go and must be repeated.
Add about 2 tablespoons of mustard to your coolant. The mustard will migrate to the leak quickly and make an instant seal. The surplus mustard will melt into your coolant and just go away. The second solution is to add black pepper to the radiator. Like the mustard, this will require about 2 tablespoons of pepper. Both of these remedies are available in packets at fast food restaurants. They are temporary fixes until you can get somewhere for a permanent solution.
Published in: Do-It-Yourself