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you're not experiencing "low" pressure, just not "high"
Posted by Aero'ed (more from Aero'ed) on Tue, 15 Feb 2011 09:39:25
In Reply to: Higher pressure?, Darin, Mon, 14 Feb 2011 13:08:59
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If you have an open system (gross leak), then the system can't build normal pressure. A 50% ethylene glycol solution has a boiling point of approximately 225F at atmospheric pressure. Take that up to 2 bar (14.7 psi), and the boiler temp rises to approx. 265F.
So, a higher system pressure will keep your coolant from boiling (which is bad).
Where I think Les is leading you, is that the air in the reservoir acts as an expansion tank. Air is compressible, solution is not. As your coolant heats, it expands (even as it doesn't begin boiling). A certain amount of expansion capability is required, or something has to give. Where I might disagree with Les is the assumption that this leads to a leak. Shouldn't the cap allow pressure relief? Granted, the cap could be bad, happens all the time, but I suspect more typically they go bad low, i.e., start relieving air/coolant at lower temp/pressure.
Ed
2007 9-5 Aero SC [60th]
2004 9-3 Aero SS
2005 9-5 Aero
2005 9-5 Arc
posted by 205.196.151...
Posts in this Thread:
- Coolant leak, Darin, Mon, 14 Feb 2011 08:16:21
- Re: Coolant leak, Benjamin, Wed, 23 Feb 2011 08:17:39
- I'll bet you 100 bucks that the reason is..., Marcin, Mon, 14 Feb 2011 16:09:38
- Re: Coolant leak, donnrandall, Mon, 14 Feb 2011 13:46:03
- year and miles on coolant pump? n/m, Dean, Mon, 14 Feb 2011 13:22:02
- most people overfill the coolant, LesH, Mon, 14 Feb 2011 12:22:01
- Re: Coolant leak, Paul in NM, Mon, 14 Feb 2011 08:20:28
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