Just curious, but alot of people here have problems with air bubbles in the coolant. The 3rd gen uses an AST -=Air Seperation Tank=- that is part of the coolant system to seperate air from the system. Would this be ideal for us? How exactly does it work?

 

People have trouble with bubbles in the coolant because they are lame and don't know how to bleed out a modern cooling system.

Or

They have failing coolant seals

 

What he said. I've never had a problem with air in the system after refilling it.

 

^^^
Ditto! It's super easy if you understand how to bleed the system...

 

Nobody even wanna answer the poor guy's question?

 

I'm sure it can be done, but I just don't see the point I guess :|

 

I do, +1 for laziness and engine bay complication.

 

FD's have them cause of the relatively low position of the stock radiator.
Like Icemark said, people are just too lazy to bleed the stock FC coolant system good enough to remove all the bubbles.
It only takes me like 15 minutes if I need to invade the cooling system for whatever reason...

Run engine with radiator cap off...
Once thermostat pops, you'll see the coolant level drastically drop.
Keep refilling until it starts to overflow - cap it when it does this.
I've never had a problem with bubbles or the LOW COOLANT buzzer going off doing this.
BTW, this is for S4 cars with the rad cap on the thermostat cover.


-Ted

 

most of the 3rd gen guys remove the ast also. . .

 

thx, that answers that

 

Dont they use the filler cap portion of the S4 thermostat neck/cover?