expansion tank cap - Pressure

[Brett Dikeman]

At 11:00 AM -0500 5/24/02, Steve Kramer wrote:
>All this talk about the coolant system is really timely with my v8.
>Replacing the expansion tank helped.   I have also replaced the upper
>radiator hoses. I also bled the system yesterday after I got some errant
>temp warnings - even though the temp was at the 100 hash mark.  Now I hear
>about the cap.  I bought one becuase I was hearing some hissing coming from
>the cap.
>
>Everything is doing fine.    My question is this - I'm not a gearhead - why
>do you need the coolant under pressure ?  The system is moving the fluid
>through the radiator via the pump.  Does the pressure keep the coolant temp
>down ?

The higher the pressure, the higher the boilover point; this is why
water boils faster at altitude(and why you can get water to boil at
room temperature using a mityvac attached to the lid of a jar.)

What I'd like to know is how to bleed the 200q20v's system...

Brett
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