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Steve Tinker · 08-29-2012, 01:34 AM

Greg has a point.....
To be honest, this is the first time I have heard that the bleed valve lifts off its seat under normal driving conditions.....This valve vents to atmosphere, not to the coolant bottle.
Those of us who change our coolant without a vacuum pump drive for several heat cycles with the valve flipped open to release any air bubbles trapped in the system, but I assumed that the valve only opened to atmosphere when excessive pressure built up in the cooling system.
Perhaps some of our resident experts can comment....

08-29-2012, 01:34 AM	#12
Steve Tinker Registered User Join Date: Dec 2008 Location: Queensland, Australia Posts: 1,522	Greg has a point..... To be honest, this is the first time I have heard that the bleed valve lifts off its seat under normal driving conditions.....This valve vents to atmosphere, not to the coolant bottle. Those of us who change our coolant without a vacuum pump drive for several heat cycles with the valve flipped open to release any air bubbles trapped in the system, but I assumed that the valve only opened to atmosphere when excessive pressure built up in the cooling system. Perhaps some of our resident experts can comment.... __________________ 2001 Boxster S (triple black). Sleeping easier with LN Engineering/Flat 6 IMS upgrade, low temp thermostat & underspeed pulley. 2001 MV Agusta F4.