leeboy

AlpineRAM

You will need to flush the heter backwards, and if you let the pure water drain out afterwards, maybe help a little with compressed air, and let the engine run for a time with the antifreeze in there before the truck is exposed to freezing temps you should be good to go.
If a shop does a backflush of the cab heater and then parks the truck outside in winter without having circulated the coolant... there is a possibility of cracking the core.
In older vehicles the heating was regulated by opening and closing a water valve to admit hot water to the cab heater.. the Dodge always has hot water flowing through the heater, and directs the air either through the heater or around the heater to adjust heating.

SIXSLUG

I wouldn't think you would need to worry about this, I can hear mine gurgling every time I start it in my driveway (slopes about 20%, nose downhill),,,,,probably due to it currently leaking and fogging my windshield.... Alpine always has good advice.

AlpineRAM

Hi Kurt!

Fogging the windshield is bad- any leak leads to reduced pressure in the cooling system, meaning the coolant can boil on the hot spots.
Cummins recommends changing the radiator cap annually in industrial applications- because the pressure is needed to avoid head and head gasket failures.
Remember- water is a good medium for heat transfer- water vapor (steam) is a good insulating medium....

SIXSLUG

Interesting, my head gasket is weeping at the front right corner also, got everything to repair, just haven't had any time.....

AlpineRAM

Please do a pressure check after fixing the known leaks. No pressure loss is allowed.
A T-Stat that opens at 190F means that the average temp in the block and head is only 22F lower than the boiling point of water (at sea level, it only gets worse up from there)- the head goes a bit higher than average... (depending on load, coolant flow, moon phase etc)

But if you add about 14 psi of pressure the boiling point goes up to 244F, meaning more than 50F (more than double) the reserve before we stop cooling and start insulating the hottest part of our engines.
Check for leaks and have a good radiator cap. A good investment.

SIXSLUG

Thanks, Alpine, I'm gonna get after it!