Pressure testing water jackets, 4.0, 4.6 block.

[Thunderchief]

In my endeavours to discover whether my 4.6 block is sound, I need to pressure test it. Obviously I need to blank off the water passages, then pressurise, if there are no leaks it should maintain pressure, if there are any significant leaks then pressure will drop rapidly. What pressure should I go to on a cold block? I was thinking around 3 bar or 45 psi. Anyone know what pressure is considered ideal?

Thanks in anticipation.

Andy.

[Mc Tool]

I been thinking the same with my block . I figured Id go with the rated pressure of the radiator cap .......to start with

[stevieturbo]

Ideally you'd test it on a warm block, as hairline cracks might seal well when cold, but get much bigger when warm.

Normal cooling systems usually operate around 1 bar at most, so a 2-3bar test would seem reasonable. And it's not a large or rapid loss in pressure....it would be any loss of pressure is a concern.