How to Check a Toyota Radiator
- 1). Lift the hood and remove the cooling system filler cap. Make sure the engine is cool before removing the cap. Fill the reservoir with water as necessary to bring it within an inch from the top. This makes it easier to pump pressure into the system.
- 2). Pump the pressure tester to 15 lbs. of pressure and watch to see if the gauge drops quickly. This would indicate a leak. Inspect the radiator front and back and side to side for leaks. Look under the vehicle for leaks that otherwise are not as noticeable. If the radiator is leaking, water will be dripping from under the car. If there are any leaks, the pressure tester will definitely make them show up.
- 3). Check the engine completely for any leaks that may have given the impression that the radiator was leaking. Check the reservoir also. If no leaks are found, turn the handle on the tester to release the pressure. Check the radiator cap for a torn rubber seal.
- 4). Remove the tester and replace the cap on the reservoir. Start the vehicle and allow it to warm up.
- 5). Shut the engine off once it has warmed to normal operating temperature. Feel the radiator for cold spots indicating the radiator is plugged up. This will have to be done on the engine side of the radiator since the air conditioning condenser covers the front of the radiator. Make sure that there isn't anything blocking the flow of air through the radiator. If it passes these tests. the radiator is good and there is another problem causing overheating.
Source...