greg8453

Raise the front end as high as possible to get ht air out.

hhrumadbruh

Does it matter if the filll cap is on or off? Engine running or just on ignition then run heater on high while filling?

RJ_RS_SS_350

Fill it, drive it, park it overnight nose high.

Next day, take the pressure cap off, top it off. Replace pressure cap. Drive it, park it overnight nose high.

Repeat for several more days, until you remove the pressure cap and it doesn't need topped off. But continue to check, maybe once a week.

Oldblue

Read my directions, they are clear and concise .

donbrew

That would require scrolling.
The reservoir bottle is not pressurized, it just collects overflow from expansion and refills on contraction of the coolant via the pressure cap.
In normal operation the bottle will fill when the engine is running then contract when the engine cools down. It is important to notice there is a "cold fill" line on the bottle toward the bottom were there is an indent. Unless yours has a surge tank instead (that is pressurized).

Oldblue

Our HHRS never had a surge tank, cobalt’s and pursuits did.

donbrew

2006 did. Maybe 2007 2.4l.

Oldblue

I’ve worked on 2.2 and 2.4 2006 and neither had the surge tank. Our member here the_shmoo his 2006 was built in Oct 2005 , no surge tank .
I’ll keep looking 👀 .
the surge tank system burps much easier and better than the overflow style . It used that port just above the rad hose in the cylinder head .
My 2018 Terrain has that surge tank system

PulpFriction

The surge tank is slightly more costly and complicated but a little better; no coolant exposure to oxygen. Thought about upgrading to a surge tank but concluded it's not worth the trouble. I've wondered why the Cobalt got the surge tank. Might have had something to do with available space; maybe they want a recovery tank to be below the pressure cap, although I'm not sure why.

donbrew

The shop manual says 2006-2007 have surge tanks, I'm going by that info, not personal experience.