How to Mend a Leaking Radiator

Fix a leaking radiator before you continue driving or you could, among other things, crack your engine's head gasket.

If your car's radiator leaks coolant, your engine could overheat, potentially permanently damaging it. Mend a leaking radiator as soon as you notice there is a leak to avoid extra repair costs. You can save money by fixing your radiator yourself, if you get to it in time, and avoiding the expense of buying a new one. There are several possible causes for a radiator leak. For instance, it could be caused by a faulty hose, the radiator cap or a crack in the radiator's core.

Instructions

1. Open the hood of the vehicle and check to see if there is a leak. With the engine cool, open the radiator cap to see if your coolant level is low. Another obvious sign is a green or orange puddle under your car. Keep in mind that radiator coolant will kill your pets, which will try to drink it because of its sweet smell.

2. Locate the leak. Start the car and inspect your car's radiator and the hoses coming in and out of it.

3. Replace any leaking hoses. If the leak comes from the radiator cap, replace the gasket. If that doesn't stop the leak, buy a replacement cap. If the leak originates from the body of the radiator, you can try fixing it with a cold weld epoxy. This is a temporary fix but can help in an emergency.

4. Locate the crack in the radiator. Empty the coolant in the radiator and collect it in a container. You'll find a petcock at the bottom of the radiator; turn it with a wrench to drain the fluid. Clean the area around the crack, let it dry, and apply the epoxy. Let the epoxy dry. Refill the radiator and check for further leaks.

Tips & Warnings

• Do not open the radiator cap or touch the radiator while it is hot, or you may get burned.

• Try cracking a raw egg into your radiator if you are in an emergency. The egg white will plug a small hole in your radiator. Another common DIY emergency remedy is to pour pepper into the radiator.

• Using epoxy to mend a leak is a temporary fix. Take your car, or just the radiator, to a professional mechanic.

References

• The International Heat Transfer Association: Consumer Tips
• Radiator: Radiator Leak

Resources

• Popular Mechanics