On Fri, 6 Jun 2003, Dennis Haynes wrote:

> The spring in the rpesure cap will have the same force regardless of
> altitude, so the pressure inside the colloing system will not be
> effected.

The *gauge* pressure -- the difference between the pressure inside the
cooling system, and the outside pressure -- won't be affected.  But I
assume the absolute pressure in the cooling system will be lower, because
I think the cap just compares the pressure inside the cooling system to
the pressure outside it.  It'd have to have a vaccuum chamber of some sort
built in, to maintain an absolute pressure.  Maybe it does and I just
don't know it.

David Brodbeck, N8SRE
'82 Diesel Westfalia
'94 Honda Civic Si