At 09:59 AM 5/9/2002, Jay L Snyder wrote:
>the passenger side wiper and started the engine.  Pressure goes up to 3 or
>4 psig pretty quickly, and after 5 minutes or so, climbs to 12 to 13 psig.
>Revving the engine causes a slight increase, but at steady rpms, it again
>levels out around 12 psig.  This is at or near the cap pressure setting.

Jay, I bet if you measure back at the engine you'll get a lower reading --
I think operating pressure is typically around 5-7 psig.  I think you're
seeing the effect of the water pump pushing against the closed thermostat
or perhaps a plugged radiator?

Darrel's been running a pressure gauge for a long time and I think he
posted some numbers once that agreed with what I saw when I hooked a gauge
to the pressure cap (with the check valve jammed open) for a few days --
well under ten running in normal temperate conditions, spikes up for a
while after you shut down, eventually goes down to slight vacuum after
cooling overnight.

david

--
David Beierl - Providence, RI
  http://pws.prserv.net/synergy/Vanagon/
'84 Westy "Dutiful Passage"
'85 GL "Poor Relation"