Pressure test coolant with intake off?

[rmr2122]

I’m replacing all coolant system components on my 3.0 and I want to pressure test the system before I reinstall the intake. Can I reconnect my battery to run the aux coolant pump so that I can fill the entire system? Or what would be the correct way to do this? All the wiring plugs are disconnected so I don’t want to turn the key to 1 and cause a ton of problems. My valve cover and coils are also out. Any ideas?

[Effduration]

I do this every time I replace coolant pipes with intake off..Test coolant pressure before reinstalling intake.

find an old thermostat housing (your old one? Ebay?), take the thermostat out, leave the probe in. Make sure it has a decent gasket.

Install all hoses/components of your cooling system along with your gutted thermostat. Fill it with distilled water, no need to bleed it. Pressurize to <20 psi. I use a compressor and m10 male to 1/4 NPT fitting that screws into bleed screw hole. You can also use a free pressure tester from Autozone or other free loaner tool that screws onto expansion tank cap.

Pressurize and look for leaks..particularly near the coolant pipes where they enter head and engine.