Radiator flush

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GTyankee

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just remember, your garden hose has at least 50 pound of water pressure.
your vehicles coolant pressure is no more than 12 pounds

so keep your back flushing pressure down low, many times radiator shops will use air pressure to blow the water out of the HVAC heater.
Once the water is blown out, the lines should be at least partially open
You can then use RMI 25, as mentioned above, or some people choose to use CLR, which is very acidic.

Youtube has several videos on back flushing

The HVAC BOX is under the dash
if you remove both Glove Boxes, you can see 2 of the HVAC Actuators
#1 is almost straight back from the upper glove compartment,
it allows fresh air to enter the cab

#2 can be seen through the lower compartment box, by looking to the left, using a flash light is easiest.
( you can work the controls & watch the actuators work
#2 is called the BLEND DOOR

numbers 3 & 4 are called the MODE doors
3 & 4 Actuators are hiding behind & below the HVAC Controls
you have to remove the center stack that surrounds the radio to get at them
watching a YouTube video really helps to get at them
if you have a full floor console, it is quick & easy

each actuator is held onto the HVAC box by 2 screws
the rod that is connected to the actuator, is also connected to the door that is inside the box
 

nascar72

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Sounds like a clogged heater core. Blend door issues are rare on the 4th gen trucks (it was more a 3rd gen issue). It doesn't take much to reduce the heat, the slightest bit of restriction or air in the heater core will drastically reduce the heat. I've been down this road several times. Try flushing first and see if that helps. The video below is the best way to do it. Also make sure you get all the air out of the core.

I've got a 3rd gen 2500 5.7 and I did a complete flush on the system and reverse-flushed the heater core for about 20 min and the other way for another 20 min and everything was pretty clean and even before I attempted to drain the existing coolant at the time, it looked pretty clear and had barely no debris/crud whatsoever in it and on the driver's side I still get BARELY lukewarm heat vs very good heat on passenger's side. Same thing in the summer time with the A/C. Just cool air on my side and freezing cold on passenger's side. So In my mind it's pretty obvious that it would be the HVAC temp blending actuator. It would be just a simple matter of having enough time and will power to take the whole dash apart and reach in for the HVAC box to fix it once and for all...lol! At least I still get good heat on both sides on the DEFROST mode. Oh well...maybe I'll just fit in one of those 12v heaters on my side to compensate lol!
 

Dusty

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I've got a 3rd gen 2500 5.7 and I did a complete flush on the system and reverse-flushed the heater core for about 20 min and the other way for another 20 min and everything was pretty clean and even before I attempted to drain the existing coolant at the time, it looked pretty clear and had barely no debris/crud whatsoever in it and on the driver's side I still get BARELY lukewarm heat vs very good heat on passenger's side. Same thing in the summer time with the A/C. Just cool air on my side and freezing cold on passenger's side. So In my mind it's pretty obvious that it would be the HVAC temp blending actuator. It would be just a simple matter of having enough time and will power to take the whole dash apart and reach in for the HVAC box to fix it once and for all...lol! At least I still get good heat on both sides on the DEFROST mode. Oh well...maybe I'll just fit in one of those 12v heaters on my side to compensate lol!
You could have another issue, but of the techs I know they all seem to be of the opinion that Hemis are hard to burp (= get all the air out).

Regards,
Dusty
2019 Ram 1500 Billet Silver Quad Cab 2WD, 5.7 Hemi, 8HP75, 3.21 axle, 33-gallon fuel tank, factory dual exhaust, 18” wheels. Build date: 3 June 2018. Now at 81758 miles
 
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Runaround

Runaround

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Can the bend door actuator be viewed without taking the dash apart?
 
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Runaround

Runaround

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I’ve read also the hemi is hard to burp. What is the best way to burp one and how do you know it is burped?
 

Burla

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maybe I'll just fit in one of those 12v heaters on my side to compensate lol!
You either country or have a lot of country in you somehow, make some lemonade out of those lemons.
 

GTyankee

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Bleeding the coolant system of a HEMI powered vehicle is actually quite easy

 
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