Just replaced my lower intake gasket and had to drain the coolant down of course. I've got a coolant system pressure tester, can I go ahead and do a preliminary press test without the system full? If the gasket is good it will hold air or liquid pressure, right? Or will the expansion tank being empty short circuit my efforts? Just want to make sure my new gasket is holding.

 

Yup. Did just that when I did my gaskets.

 

Cool thanks. So far got it up to 12 psig, holding steady crossing my fingers.

 

held 16 psig for 30 mins, 1/2 psi drop. call it a good night. try again tomorrow, got to get some rest for work!