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Old 11-30-2010, 02:15 AM   #30 (permalink)
mechman600
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Quote:
Originally Posted by UFO View Post
No way. If there was that much pressure, you'd empty the contents of the radiator on the ground. Cooling systems typically use 12-15 psi caps.
The pressure in the reservoir is 12-15 psi where there is no flow. This pressure is created by the expansion of the heated coolant in a confined space - the cooling system - not by the pump. In the block immediately after the water pump, the pressure is much higher. I have checked block pressure on many engines when I suspected a broken water pump impeller causing an overheating problem. 40 psi is not uncommon. Don't believe me? Then hook a gauge and find out yourself.
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