Lorn-interesting point

The other day when I parked up the ambient temp was aropund 15 degrees c. When I returned to fly two days later the high pressure guage registered about 500 psi and the ambient temp was 33 deg C. (Typical Melbourne weather).

I took off and the gear retracted ok but I wonder if the pressure had been higher...

I know others crack the valve before shut down-I presume this is done with electrical power to the system i.e. before the master is off?

Do some leave the dump valve open when the airplane is parked?

Gerard