Just something that always make me go hmmmm when I open the hood of my car.

What is the purpose of the extra tube that is attached with the tube that is connected to the anti-freeze resoiver (sp) to the radiator. It doesn't go anywhere and isn't connected to anything, is it used as a draining mechanism in case the anti-freeze overflows from somewhere?


Hey I'm a car novice and just trying to learn as I go :hide:

My guess is it is an overflow if coolant in the resovoir gets too high, it will start to spit it on the pavement. It has to be nearly overflowing the cap to do that. I keep mine faily full, well above the "full hot" line. VERY rarely has it actually overflowed anything.

It is also where pressure is released from the radiator. If you didn't have the open hose and your resevoir cap is the kind that seals tight you can see the antifreeze start to boil. Cars that don't have the hose coming out of the top usually have a style of cap that can release pressure.