Well, a week or so ago my heater water valve (connects to one of the pipes that goes to the heater core; the bottom one; I think it's the "from" pipe) sprang a bad leak (I found it when my temp guage rose perilously high). I bypassed it with a completely new hose and right now it's just sitting there duct taped to the new hose. What, exactly, does it do? I think it sends a vacuum signal for acc, but I tried my heater and it still seemed to work (I didn't try it very long, though, as it was about 100 degrees at the time). My hayne's manual has said nothing about what the function of the device is.

I'm driving a 1988 volvo 760 wagon, turbo.

BTW I also had a lot of unrelated oddities with the emergency brake in this same car; will get to that in another post.

Thanks,
Bob