How to Repair a Car Radiator Core
The radiator in a car serves the important role of monitoring the car's coolant system. A rock or other random object from the road can hit the radiator and damage it, allowing antifreeze to leak out. This can lead to the car overheating and can even cause serious damage to the engine. Small holes to the radiator core can be repaired once the radiator has been safely removed from the vehicle.
Items needed:
- Pressure washer or high-pressure garden hose
- Water tank large enough to submerge the radiator
- Compressed air
- Wire brush
- Blow torch
- Solder
- Safety goggles
- Safety rubber-tipped gloves
- Liquid flux
Prior to starting the cleaning process, make sure you are wearing the safety goggles and gloves to prevent any injury.
Instructions:
- Clean out the garbage out of the radiator coils with the pressure washer. This includes dirt, grime, and insects that have accumulated in the radiator over time. Cleaning the coils makes the tank more visible.
- Close off all openings other than the one you will be sending air through using the caps. These openings include the filler necks and the stub for the heater. Make sure the caps and size plugs are the proper size to prevent them flying off, and potentially causing injury once the pressurized air enters the radiator.
- Find a single opening and attach an open stem plug on the opening. This is used to let in pressurized air later.
- Submerge the radiator into the water tank.
- Turn on the air, but to no more than 15 pounds per square inch. The bubbles in the water reveal the leaks in the radiator core. Take note of the leak locations.
- Scrub the radiator tubing and core using the wire brush to remove any paint and dirt that has accumulated on the radiator core. NOTE: If metal parts from the core fall off when you are scrubbing, this indicates that the core is rotted and the radiator will have to be replaced. Otherwise, continue cleaning until the paint and dirt are removed. It is now ready for the next step.
- Spread liquid flux, with a small brush, onto the damaged tube. At the same time, use the torch to apply solder to the tubing.
- Solder the tubing so that it is even with the other tubing, filling the hole in the tubing.
Once the solder has cooled, put the radiator back into the water tank. If there are no leaks, the repair is complete.