Coolant pressure testing , would expect a slow drop ?

[Hoofa]

Well fixed my first prob which was the ally rad, I pressurised the system and within minutes saw the pressure drop and leak to appear. Replaced the rad and though i would do another check, the system still looses pressure say 1/4 bar over 4 hours, is this normal or would you expect no pressure drop ?

I cannot see any leaks this time round?, your thoughts chaps ?

[Colin RedGriff]

Normally I wouldn't expect it to drop off if the system is cold. 1/4 bar over 4 hours is very slow I would say but it depends a bit on how high you pressurised the system

If you pressurised it to say 2 bar then i would expect it to go down as it will leak past the pressure cap.