Originally Posted by
Mats1985
Iv changed the rad had a pressure test and no leaks anymore changed the matrix and all still the same after a jurney turn engine off and pressure there it dosnt run hot anymore just pressure when everything is turned off
There is usually a small amount of pressure in every cooling system which serves the purpose of raising the boiling point as Jano said.
It's the heat which cause the pressure to rise in the first place, so until it cools down the pressure won't go anywhere, unless you take the cap off expansion tank. This is a bad idea if its still red hot!!