Air in Water System

[wattawog]

HI guys, just a quick question. Im in trouble with my radiator hose connecting to the back the block..

I was told to make sure i don't leave any air in the water system. What i was never told is how the hell do i do that ?
Can anyone please help me?

[wattawog]

I was told this from a mate. I guess now ive learnt that its all nonesense & he has no clue of what he is talking about.
I just wanted to confirm it with you guys at JW.
Thank you....... 8)

[cooperluke]

The air question is not has simple as that...

I think maybe they were talking about little air bubbles in the fluid. Those are due to head gasket problems.

And there are a few cars that are prone to form air deposits inside the block/head, that can cause those bits to overheat. But that normally only happens in old cars, nowadays not so normal.

[lev_p]

There is such a thing.
The point is, when you completely change cooling fluid, some air gets trapped in the cooling system. It may bring the system to overheating.

What you do is rather simple, and takes about 15 minutes.
First, you have to find bleeding taps on your radiator, block, thermostat housing, head, internal heating connectors. THe amount and placement varies according to make. Open them all up. Fill in the cooling liquid into header tank, until it runs from radiator bleeding valve without air bubbles. Close the radiator bleeding valve and start your engine. Keep adding cooling liquid as it's drawn by the pump. You have to make sure that the level of the cooling liquid in your header tank is always higher than the highest level of cooling liquid in the head.
As soon as you see liquid that comes from some valve is without any air bubbles, close that valve.
Let engine heat, until the fans cut in. When they cut in, a lot of liquid gets drawn in at once. Top up to the manufacturer's specified maximum, wait until fans cut in once again and close the header tank.
Here you go, you just bleeded the cooling system.
Ah, wait, I forgot something. It's better that when you do this, have the interior heating turned on. Also, have some spare cooling liquid (e.g., if your car requires 5 litres, get 8, as it spills).
And, if someone can give you a helping hand - that will be helpful for the first time.

Good luck! PM me if you have troubles....

[coombsie66]

The only precaution you need to take, is dont just fill up an empty system, close the lid and forget about it. Fill the system, then start the engine to circulate the coolant, then turn off, the air locks should have found their way to the header tank, refill to the specified mark and repeat untill the level remains constant.
No air locks will remain, as the bubbles will always try to find their way to the surface, and if your header tank is the highest point in the circuit (radiator top might be too, so if it is then top up from the radiator), then with a little help from the water pump all the air will find its way out.

[lev_p]

Well, I described a classic method from Haynes books. What combsie66 said is also perfectly alright, as long as you remember to top up after first run. Just don't drive the car until you finished with cooling...
Thinking of it more, there might be a difference between US, Euro and Jap cars in this matter.
I remember the only US vehicle I drove, a Chevy Rally STX. Over there to get to the heating connectors or to the head you would have to dismantle half of the car...
On Euro and Jap cars, all these valves are easily accesible. Well, except mine. I've got a French car, and they've built in such way, that header tank upper level is below the top level of the head
Anyway, good luck

[T-Bird]

question is did you use the Pink Poly Glycol specific to Audi and VW or did you use normal Ethyl Glycol (green usually) and You know to make it a 67/33 mixture.