Whats with this screw for releasing air?

[madcabbie]

Just read a thread pertaining to changing the coolant.

You all mention that there is a screw that you remove to release air from the motor. Why is this needed?

I have never owned a turbo car prior to my new gti-r, and i plan on doing some services like oil and coolant just so I know when they have been done first. But any other car that I have flushed the cooling system, I have never needed to release air.

Could someone please explain the reason as I am very interested in this.

I want to know as much as I can about my R.

Cheers

 

[Odin]

The screw is there to get rid of the air at the highest point to stop you getting an air lock in the system .




rob

 

[Fast Guy]

It's the same idea as the bleed screw on your brakes, ie to let the air out of the system as Rob said

 

[geetee]

The idea is you loosen it when you fill the collant - so air can escape.

I've always found it does sod all and no coolant comes out of it.

Personally, I fill the rad and the expansion tank.... give the hoses a good pummelling.... top up the rad again and start it.

Wait for it to warm up a bit (idling) .... switch it off. As it cools it drags all the fluid from the expansion tank into the system... top up the tank.

Repeat a couple of times.... no probs.

Although I believe some peeps have probs with airlocks in the past - so don't take my word for it!

Cheers
GeeTee 8)