Radiator swap and fill question.

[SandDiesel]

Just swapped in an aluminum, topped of with coolant and let it run for a bit. Are you supposed to let it heat up with the rad cap off until the thermostat opens and top off as it flows? Or cap on, let it cool back down then top off? Can't remember it's been many years. The thermostat does have a hole so the air can "burp". Thanks anyone.

 

[b5rt]

Great idea with the hold in the stat. I've done this on my last 3 and it helps get rid of the air. I always fill it slowly, sometimes you'll hear a "burp" from the air escaping, leave it about 3/4 to 1 inch below bottom of fill hole. It also helps to have the front of car slightly higher than the rear. Run it with the cap off so you can monitor the fluid flow and add as needed. Once you know the stat is working right and the level is good, again about 3/4 inch below bottom of fill hole, put on the cap. Let it run for a few minutes or drive for a few blocks, then shut it off and let it cool down. Recheck level once it's cool and to ensure there's no leaks once pressure has built up.

 

[SandDiesel]

Cool, thanks!