Coolant Drain and Refill

Step by step instruction on how to perform a coolant flush. This article was performed on a Chevy Tahoe but it pertains to most vehicles.

Difficulty Rating: 2 of 10

Tools and Supplies Needed

  • Coolant
  • Coolant catch basin
  • Protective eyewear and gloves
Begin with the car on level ground in park with the emergency brake set. The engine should be cool before beginning to avoid pressure inside the cooling system.

Step 1 - Locate the radiator fill cap which is usually in plain sight and on either the radiator itself or on the coolant reservoir.

Locating Radiator Cap

Step 2 - After the cap has been located, remove it slowly while allowing any residual pressure to bleed off. Caution: The cooling system will hold pressure when hot so be careful when opening the radiator cap.

Releasing Residual Pressure

Step 3 - Once the radiator cap has been removed, locate the radiator drain valve. (Note: Some vehicles are not designed with a valve, in this case the lower radiator hose must be removed from the radiator to drain coolant.)

Locating Coolant Drain Valve

Step 4 - After locating the coolant drain valve, open it by turning the valve counter clockwise.

Draining Radiator Coolant


Written by
Co-Founder and CEO of
35 years in the automotive repair field, ASE Master Technician, Advanced Electrical and Mechanical Theory.


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Article first published (Updated 2015-01-06)