Here's a general procedure. Specific locations of components may vary slightly depending on the exact trim level and modifications. Consult your owner's manual for precise locations.
Tools You'll Need:
* A large drain pan (at least 5 gallons capacity)
* A wrench (likely a 1/2" or 9/16" for the petcock, but check your vehicle)
* A funnel (optional, but helpful)
Steps:
1. Locate the Radiator Drain Petcock: This is usually located at the bottom of the radiator, on the driver's side. It's a small valve.
2. Position the Drain Pan: Place the drain pan under the radiator drain petcock. Make sure it's large enough to catch all the coolant.
3. Open the Drain Petcock: Carefully turn the petcock counter-clockwise using the appropriate wrench. The coolant will begin to flow out. Be careful, as the coolant is hot even after some time has passed.
4. Open the Radiator Cap (Optional but Recommended): Opening the radiator cap (after the petcock is open and coolant is flowing) will allow for quicker and more complete draining. Remember to do this *after* the initial draining has begun to release pressure more gradually. Again, be cautious of the hot coolant. Let it cool down first if needed.
5. Wait for Complete Draining: Allow the coolant to drain completely. This may take some time.
6. Close the Drain Petcock: Once the draining is complete, close the petcock by turning it clockwise until it's tight.
7. Dispose of Coolant Properly: Coolant is toxic and should be disposed of responsibly. Check with your local auto parts store or waste disposal facility for proper disposal methods.
Important Considerations:
* Type of Coolant: Note the type of coolant you drain (usually 50/50 mix of antifreeze and water). This is important when refilling.
* Refilling: After draining, you'll need to refill the radiator with the correct type and amount of coolant. Refer to your owner's manual for the specifications. It's also a good idea to bleed the air out of the system after refilling (this often involves running the engine for a few minutes, then topping off the coolant).
* Engine Block Drain: For a more thorough drain, you might also consider draining the engine block. This usually involves removing a drain plug located on the engine block itself. This is usually lower and near the oil pan. This requires more mechanical knowledge.
* Safety First: Always wear appropriate safety gear, including gloves and eye protection, when working with coolant.
If you're not comfortable performing this task yourself, it's best to take your Tahoe to a qualified mechanic. They have the experience and tools to do it safely and efficiently.
