From the 2nd paragraph of the referenced doc,

"The coolant bottle and cap help maintain pressure on this system, keeping it
sealed from pressure loss.  As pressure is raised on the cooling system, this
lowers the boiling point of the coolant."

Huh?

//Jack
 '85 GL

Date sent:              Fri, 27 Apr 2007 11:12:32 -0700
From:                   gary hradek <hradek@YAHOO.COM>
Subject:                interesting site about coolant
To:                     vanagon@GERRY.VANAGON.COM
Send reply to:          gary hradek <hradek@YAHOO.COM>

> http://faculty.ccp.edu/faculty/dreed/Campingart/jettatech/coolingmaint/index.h
> tm