In the near future i plan to drain out all the old antifreeze from my car. I own a 91 740 turbo and i know it is a closed system and i see the bolt to loosen to drain from the bottom. But having never do this before on a closed system, how would i re-fill it when i am all done? Would i just continue to fill up the overflow tank untill it cant take any more? Or am i wrong? Thanks a lot.

 

yeah! just drain the old coolant, and fill it on the reservior. until the is in max level. and drive the car around to operating temp recheck the level.

 

Thanks a lot.....i just wanted to make sure.