I just bought a new pressure gauge. I've been buying a load of tools for this. (ex: timing set) It's worthwhile since I have 2 Zetec based Foci. (ZX3/SVT)
Unfortunately, most places don't rent them for some reason.
As far as the pump goes, yes the first prime is 20 psi. 2nd prime is anywhere between 25-30. If yours was 5/10/15 etc. that was indeed bad. I guess maybe mine is weak? Not able to hold high pressure even though it holds if I let it sit?
WIERD!!!