Draining Coolant From 4.* Engine
You can easily drain about 1.5 gal of coolant from the radiator of a 4.9 engine by siphoning. All you need is 1/4" plastic tubing pushed all the way down to the radiator bottom through the neck. Full capacity of the cooling system is 11 qt. The procedure takes a few minutes and there is no mess at all! Refreshing the half of the coolant say, every spring makes sense. Do not forget to add two- three Bar's Leaks golden powder in tubes from Wal-Mart (see the picture) or pellets of GM supplement. It's the same stuff (ground ginger roots) made by the same company.