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How to Check for Cooling System Leaks in a Toyota Corolla

by Contributor

The financial investment in an automobile for most people is the second largest purchase he will make. To make sure this investment pay offs in the long-term, you should perform periodic maintenance checks. Checking the cooling system for leaks is one such task. In addition, if you become adept at this inspection, it can help you determine the reasons for an unexpected drop in the coolant level in the future.

Step 1

Relocate the Toyota Corolla from its normal parking spot and check the area underneath that parking space. Because coolant is usually orange, blue or green, you should have no trouble spotting any leakage on the ground. Even though you don't see any coolant, it doesn't necessarily meant there isn't a leak; the engine heat could have burned up the coolant before it reached the ground.

Step 2

Open the hood and inspect the cooling system hoses. There should be two sets of hoses. The two that connect the radiator to the engine and the two that connects the engine to the heater core, which is behind the engine near the windshield. Look for any hoses with bulges, splits or cracks.

Step 3

Examine the water pump and the gasket seal of the Toyota Corolla. The water pump is behind the engine fan and the gasket seal connects the pump and engine block. Check for any discoloration or corrosion on the water pump or the gasket seal.

Step 4

Inspect all visible areas of the radiator with a flashlight. Be sure to look underneath the radiator as rock and road debris can damage the underside of the radiator. Again, the telltale sign will be discoloration and corrosion.

Step 5

Verify the radiator is cool to the touch and then carefully remove the radiator cap. Opening a warm or hot radiator is extremely dangerous, because the pressurized coolant inside can reach 250 degrees.

Step 6

Fill the radiator with fresh coolant and switch on the engine. Then, turn the heater to the high setting. Let the Toyota Corolla run for about 15 minutes like this.

Shut the engine off and check all of the auto parts from the previous steps. If there is still no sign of leakage, the cause is most likely internal leaking. In which case, you should take the car to a cooling system specialist.


  • Dispose of all coolant in a sealable container as it's extremely toxic to people and pets.
  • Whenever you work on a radiator, wearing gloves and a long-sleeved shirt is always a good idea.

Items you will need

  • Flashlight
  • Gloves
  • Long-sleeved shirt
  • Coolant

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