Radiator Refill Question

89 Dakota 3.9. Changed out rad. Refilled it with 50/50 and overflow too. Will it take a few cycles for the coolant to level out and expel air pockets if any? Initially, it ran hotter (dash gauge) than normal. Had heater on high also.

You should idle it with rad cap off and heater on high for awhile to burp out any air.

Yeah, at first I did that but obviously filled the rad to high and it was burping out coolant. It cooled down and sucked up a nice amount from the overflow.

Well it might be running a little hotter because you had more water than coolant before replacing radiator. As long as it isn't running too hot you are good to go, I'd say.

Care to elaborate on that? Not sure I understand.

Sure, I care to elaborate on this. Pure coolant runs hotter than pure water. Yes it will boil eventually, and corrode. Racers run straight water because it transfers heat better. So, I thought if he had not flushed in awhile and was running mostly water, it was running cooler prior to his maintenance.

For all you guys that believe you can never have too many tools, get yourself a Lisle #24680 spill free funnel. This thing worked awesome. Dash gauge back to barely above the warm line and heater was HOT! The most surprising thing to me was you can remove it from the rad with the coolant piping hot and not spill a drop. And the excess in the funnel right into the overflow. Obviously never had one, so I'm a little giddy with it.

Those do work well.
I made something that works the same way with the prestone rad mouth fitting and a length of tubing.

Position it vertical and start the engine...air is expelled and soon the thermostat opens and you have the surge that normally necessitates securing the cap, but now you can let it rise in the tube, along with more air bubbles. Then shut off and let coolant return to motor.

Less mess, and much more thorough purging of air.

Just took a look at it online. Neat. Thanks for the tip.