How To Seal Vehicle Radiator Leaks

9 March 2017
 Categories: , Blog

If your vehicle overheats or you notice oil puddles under the vehicle, it could indicate a radiator leak. Not fixing a radiator leak can damage the engine. Radiator leaks commonly occur in hoses, cores, seams, or tubes.

The good thing is you don't have to replace the radiator right away. It is possible for a non-mechanic to temporarily seal the leaks until you can get it to an auto shop. Here are tips to fix a vehicle radiator leak.

Prepare to Work

For this project, you need:

  • work gloves
  • safety glasses
  • rags
  • hose
  • eggs and coarse black pepper (optional)
  • radiator epoxy
  • pressure tester
  • brake fluid (optional)

The leak may not be coming from the radiator. Shut the engine off, and let it cool. Wash the radiator with a hose to detect leaks easier, then let it dry.

Turn on the engine. Watch for fluid leaks around the radiator, and listen for hissing noises.

If you can't see a leak, turn the engine off and use a pressure tester to identify the source. Raise the hood and lay a rag over the radiator cap. Slowly untwist the cap, and fully untwist when all the stream is out.

Connect the pressure tester to the radiator. Pump the suggested amount of pressure, and avoid going over this limit.

Seal Cracks with Epoxy

Small, visible cracks can be sealed with epoxy. Ensure the area is free of dirt by wiping it with a rag. For stubborn grime, apply some brake fluid. Let the area dry before continuing.

Break off epoxy about an eighth of an inch thick, so it can handle the pressure of the coolant system. Roll the epoxy in your hand until it is pliable, and apply it to the crack.

Use Eggs and Pepper

Eggs and black pepper can be used to fix pinhole leaks or longer cracks in emergencies, such as when you are out driving. They aren't a long-term solution, since they can clog coolant lines. However, they will stay hardened long enough until you get the radiator serviced.

Add three or four egg yolks to the radiator. Turn the engine on so the yolks can circulate through the system.

To fix a leak with pepper, turn off the motor, and let it cool. Add two teaspoons of coarse black pepper into the radiator. Pepper seals longer than egg yolk. If you are out driving, reseal the leak with epoxy when you get home.

As you drive the vehicle, check for signs of leakage. If you don't trust your skill or the radiator still leaks, take the vehicle to a mechanic.