Replaced my water pump, heater hoses, heater valve and coolant yesterday. All **seems** hunky-dory, no leaks found yet, etc. But I would like to know how long the cooling system should hold pressure after the car is fully warmed up by driving about 30 miles, then parked and shut off with the hood open. Having the hood open probably lets it cool a bit faster. It is about 65 to 70 deg. in my garage, and there is good circulation, but no direct breeze.

Judging by the highly unscientific method of squeezing the upper radiator hose, it holds pressure pretty well for at least 15 minutes after shutdown, maybe longer. But, by 2 hours later it has lost all pressure, and cooled enough to take the cap off of the expansion tank.

Is she cooling off and losing pressure too fast? Or, is this just about right? Should I become hysterical or just remain calm?
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Scott Cook - 1991 745T, 1985 RX-7 GSL-SE, 1986 Toyota Tercel (Don't laugh, it is reliable, faithful AND gets 41 mpg!)