It's a good idea to drain and fill the radiator of your Chevy Tahoe to perform regular scheduled maintenance on it and replace the coolant. Although it's not as good a service as a coolant system flush. If you are draining the radiator with the intent to remove it afterward, be aware that this is the easiest part of the that procedure and if you have to look up how to do it, you may want to consider going to a qualified technician to do it.
Park the Tahoe on a flat surface and open the hood. Do not perform this procedure under any circumstance when the motor is hot. If the motor is hot, allow time to let it cool.
Put on the safety glasses and crawl under the front of the Tahoe on a creeper if you have one. Follow the side rails of the radiator near the bottom on both sides to locate the drain plug. The location of the drain plug will depend on the motor, size of the radiator and year of the Tahoe. Some earlier models may need to be drained by removing the lower radiator hose, but most later-model and aftermarket replacement radiators have drain plugs. If the drain plug is present, place the drain bucket strategically beneath it and turn the plug counterclockwise. You may need to convince it with the channel locks. Make sure to be out of the line of fire when the drain plug opens.
Move the clamp on the lower radiator hose by squeezing it with the channel locks (if it's a self-locking clamp) or by loosening it with a screwdriver, if you cannot find a drain plug. Pry the lower radiator hose off and be prepared for splashing and a mess.
Crawl back out from underneath the Tahoe and remove the radiator cap. This will create an air vent and allow the antifreeze to purge more quickly from the drain plug and/or lower radiator hose.
Close the drain plug by turning it clockwise when the radiator has drained or, if needed, replace the lower radiator hose and clamp. Fill the system with antifreeze approved for your Chevy Tahoe (Dex-cool antifreeze) and allow the Tahoe to run up to operating temperature with the radiator cap still removed and the drain bucket strategically placed beneath it. This will allow the radiator system to purge air bubbles and bleed itself. Check the antifreeze and adjust the level as necessary for the next three normal operations.
