Radiator flush

[Runaround]

What is the best radiator flush for these trucks? I’m asking because I think my heater core might be stopped up. I’m thinking this because I don’t get good heat from the heater once the truck is warmed up and one of the heater hoses is much warmer than the other. I don’t know why it would be stopped up because this truck has never had dirty coolant in it. This is a 2014 model with the 5.7.
I just put a new t-stat in, a fail safe 203* stat. The radiator itself along with the upper and lower hoses are around a year old.

 

[Burla]

RMI 25 and only rmi 25. It will take any slime from system or rust and deposit into overflow tank where you can vacuum it out with wet/dry vac.

 

[crash68]

This is a 2014 model with the 5.7.

By chance was this truck built in Mexico? Easy way to tell is if the satellite antenna will be near the windshield.
I ask as it seems the HD trucks are usually the ones reporting plugged heater cores, both the 6.4 and Cummins.

 

[Hemi395]

Check to make sure the blend door actuator is working for the temp blend door. A lot of times they go bad and get stuck either on cold or in the middle

 

[Jeepwalker]

Backflush first (with a hose) to loosen any crud. Sometimes a lot comes out and that solves the issue. Do a youtube search on 'backflushing a heater core'. Obviously make sure to use distilled water or purified water with the new anti-freeze (or pre-mixed).

Yeah, Hemi395 is right, blend door actuators ..check them. A scan tool can actuate them, or if one is bad it'll throw a HVAC module code. Maybe a part store can scan that.

 

[Runaround]

By chance was this truck built in Mexico? Easy way to tell is if the satellite antenna will be near the windshield.
I ask as it seems the HD trucks are usually the ones reporting plugged heater cores, both the 6.4 and Cummins.

This truck is a U.S. made 1500. It’s not one of the problematic HD’s. I’m not even aware of a satellite antenna on this truck. It is only a Tradesman package with the AM/FM Siurrus radio.

 

[Runaround]

Backflush first (with a hose) to loosen any crud. Sometimes a lot comes out and that solves the issue. Do a youtube search on 'backflushing a heater core'. Obviously make sure to use distilled water or purified water with the new anti-freeze (or pre-mixed).

Yeah, Hemi395 is right, blend door actuators ..check them. A scan tool can actuate them, or if one is bad it'll throw a HVAC module code. Maybe a part store can scan that.

I’ve been looking at scan tools on Amazon. I will have to check and see which ones can actuate the blend doors and scan for HVAC codes.

 

[Runaround]

RMI 25 and only rmi 25. It will take any slime from system or rust and deposit into overflow tank where you can vacuum it out with wet/dry vac.

I’ll start looking for some. I’ve never heard of it before. Thanks.

 

[Runaround]

I might try switching the heater hoses at the water pump to create a back flush before I do anything else.

 

[Runaround]

I might try switching the heater hoses at the water pump to create a back flush before I do anything else

 

[crash68]

It is only a Tradesman package with the AM/FM Siurrus radio.

If it has Sirius in the radio then there's a satellite antenna on the roof. The Mexico plant builds the HD trucks and 1500s.
Trucks with VIN numbers that start with a 3 are built in Mexico,

 

[Runaround]

It says on the sticker on the door, Made in the USA. My VIN starts with a 1.

 

[gofishn]

Remove the heater core hoses, do a low pressure test to see if you got flow, through them.
If so, Blend door issue. Highly doubt core is blocked. might be gunked up but doubt completely blocked.
Does the Overflow have a ton of crud?

RMI-25 is simply awesome.

Cooling system are pretty basic and easily diagnosed.
Fixing, on the other hand, can be a bear.

 

[mtnrider]

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.

Flushing A Heater Core

Come along with Eric O. at the SMA shop as we diagnose and repair this 2013 Ram 3500 Cummins that came in with a complaint of no heat out of the dash vents. ...

www.youtube.com

 

[JW2 Innovations]

I had a Durango years back with heater item, and backflush was the fix. Incredible what came out of it and wasn't that many miles on it as I remember. Bought it new. Of coarse I did it in winter when I needed heat in Chicago.....so much fun!

 

[chopperman1]

Do NOT just flip your heater core hoses, you will put all the crap right back in your system and it will plug back up in no time. Pull both heater core hoses and simply use a garden hose on the outlet side (your cooler side) to backflush it til it runs clear.

 

[JW2 Innovations]

Do NOT just flip your heater core hoses, you will put all the crap right back in your system and it will plug back up in no time. Pull both heater core hoses and simply use a garden hose on the outlet side (your cooler side) to backflush it til it runs clear.

Yep, that's how I did it. Worked great!

 

[Runaround]

Alright guys, I did reverse the hoses for now, I think, if I didn’t put them right back on the same way but will pull them and try flushing with a water hose. I somewhat don’t really think it is plugged.

 

[Runaround]

Check to make sure the blend door actuator is working for the temp blend door. A lot of times they go bad and get stuck either on cold or in the middle

Where is the blend door you are referring to and how can I watch it operate?

 

[Hemi395]

I believe it's behind the center stack, according to this diagram anyway. To hear if its moving, turn the key to on but don't start it. Turn the fan speed to it lowest setting and then change the temp from cold to hot to cold. You should hear a motor moving as well as the sound the air makes will change.