Draining A Chevrolet Tahoe Radiator

• 1). Open the hood.
  
  
• 2). Unscrew the radiator cap from the radiator. Press down on the radiator cap with your hand and turn it counterclockwise. Lift the cap off the radiator.
  
  
• 3). Locate the petcock valve on the lower right corner of the radiator.
  
  
• 4). Place a waste oil collection pan directly underneath the petcock valve.
  
  
• 5). Open the petcock valve by turning it counterclockwise with a needle-nose pliers.
  
  
• 6). Allow the radiator to drain completely.
  
  
• 7). Close the petcock valve by turning it clockwise with a needle-nose pliers.