philiptibbs

I have a 2008 Dodge 3500 2 wheel dually with 6.7 cummins. I have installed the egr delete by Sinister and after that my heater blows cold air or hot air. I was told I have an air pocket. Is this correct ? If so what is the correct way to get rid of the air in the cooling system ? I'm new to this truck I just inherited it from my Father in Law he passed away from stage 4 cancer. I upgraded the truck so it may last as long as I can get it too. It only has 65k miles on it. I'm hoping to get 500k .

mega-engr

On the passenger side of the truck towards the rear, I believe there is an air bleed screw that is high up near the valve cover. Loosen than but don't remove it and the air should travel to that high point and out... Once the air is out then tighten it up.

philiptibbs

I just did this twice hopefully it works. Seems like the coolant is going in the overflow and not staying in the radiator. Maybe my Thermostat is bad ? But the coolant seems to be moving once the truck heats up. I tried letting the air out the bleeder screw by the valve cover. Hopefully it works. Also thanks for the info.

mega-engr

The expanding and gas bubble will want to push excess fluid to the overflow. I assume the truck comes up to temp and not under or overshoot? Unless the bubble is trapped and there is no flow then it should come to the top and out the air bleed. Did you see some fluid espaping the threads? Did you see any air at all come out?

philiptibbs

Yes both times fizzy coolant came out the bleeder screw and big air came out the radiator cap both times when it cooled down. The first time I did the bleeder screw big air also came out. I will check it again in morning. It has never over heated but it has just blown cold air. Now it is blowing hot air when I turn the heat on. I'll check in morning because I drove it to the gym and back which is about 10 miles.

mega-engr

Awesome! This all makes sense. Keep checking, sounds like there was lots of air trapped around the heater core...

philiptibbs

It's fixed air is all out.

mega-engr

Right on. Glad the root cause and corrective actions were correct :-)!