On two different Blazers I've had the pin on the radiator drain **** fall out. Thereby preventing the drain **** from staying in the radiator. You can go spend about 7 bucks and get a new one, or just do what I did to repair it.




I simply put the drain **** in where it should be then drilled a tiny hole in it, right where the pin would be when locked in place. Then put a very small screw in the hole you just made, and you're all set. It will not pull or fall out without first loosening or removing the screw. I hope this helps someone. Thanks.