how do i drain the radiator on the c5?
 

theres no slot for a screwdriver im lost

Re: how do i drain the radiator on the c5?
 

There is a real funny looking slot in the pet cock. I think I just stuck a real wide blade screwdriver in one and turned it. It only turns about 1/4 turn to be wide open.

Re: how do i drain the radiator on the c5?
 

Some have a screwdriver slot and some have a square hole that a 1/4" drive extention fits in. It turns out about 1/3 a turn also moves towards the rear of the car. I have had a car here that someone broke the little guide in the radiator for the pin in the petcock because he was pushing hard and turning, it breaks pretty easy so be careful..