How to Rebuild a Car Radiator
The radiator in a vehicle monitors the temperature and keeps it from overheating. If it is damaged it can cause serious injury to the engine. In repairing a radiator, the key is assessing the level of damage and the feasibility of fixing the radiator or replacing it. This is largely determined by the level of damage to your radiator. If there are too many cracks or other damage, it may be better to replace it.
Temporary Fix:
There are temporary fixes to the radiator that can be considered in the short-term, to keep the vehicle running until you cut it off. These are only short-term fixes and will not work if the crack is too large, if there are multiple holes/cracks or if the radiator is starting to erode. In these cases, it is always necessary to replace the radiator. Short-term fixes include using stop leak, which can be purchased as gas stations and auto repair stores. This will handle most small holes, but will not be effective for larger ones.
Repairing the Radiator:
- If these temporary fixes are not possible, repairing the radiator may be necessary. If this is the case, there are steps that must be followed to properly repair the radiator properly.
- Clean the radiator with a pressure washer, making sure that any dirt, grime or bugs are washed away.
- Close off all openings in the radiator, leaving only one opening, which you will be using. Openings in the radiator include the filler necks and the stub for the heater.
- Find a single opening and attach an open stem plug on the opening. This is used to let in pressurized air later.
- Completely submerge the radiator in a tank large enough to cover it completely with water.
- Using pressurized air, send the air into the single opening, but only at 15 pounds per square inch. Take note of the bubbles in the water. These reveal the leaks to the radiator core, and these are the areas that will need to be repaired. If there are too many holes, or they are too large to be fixed, the radiator will need to be replaced.
- Scrub the radiator tubing and core using the wire brush to remove any paint and dirt that has accumulated on the radiator core. If metal starts falling off at this point, the damage is too extensive and the radiator will need to be replaced.
- Spread liquid flux onto the damaged tube with a small brush. While doing this, apply solder to the tubing using a torch.
- Solder the tubing so that it is even with the other tubing, filling the hole in the tubing.
- Allow the tubing to cool.
- Submerge the radiator back into the tank of water. If there are no leaks, the repair is complete.