2000 radiator replace

[wired1141]

How do I go about flushing the system on this 2000 Z71 5.3L with auto trans?

[rjgti]

drain coolent and start flush, backflush heater core

[Mike GMC]

I replaced mine last year. It had a cool built in drain hose on the drivers side. It stores pointed up, just slide it out of the loop and rotate down being careful not to pull it off the drain valve. Then open the drain valve and wait, it runs slow. Watch for the rubber donuts on the locating posts on the bottom when swapping it out. My new rad did not come with them and I had to pull them off the old one.