So a while back I discovered my heater core was leaking and probably plugged since the heat output last winter was not the best. 

 I ordered and received the new heater core and evap core from rock Auto, figured I'd replace both since I would have the box out already. 

 I plan on replacing both, cleaning everything up and checking all the foam gaskets and whatnot while in there as well. Thought about the "heater treater" part but I was not having the issue that it repairs.

 Wanted to replace the dash cover as well but it's not in the budget at the moment so it will have to wait.

 Is there anything else I will need to consider while I have it all apart?

 I've read @Mopar1973Man's write up on removal of the HVAC box without completely removing the dash from the cab. I will be following that instruction for the repair.

 Thanks in advance for any input.

It will work just fine I've done at least a dozen heater cores now and still it takes me most of the day to do a full heater core and evaporator service. I do everything wash the two half of the HVAC case. Inspect the evaporator for oily spots if so replace. Then if it dry I will typically power wash and reused if in good condition. Then check the blend door shaft since it out you can easily change that plastic shaft if need. Change out the blower resistor if the ceramic is cracked. If resistor is poor condition replace the blower motor too being the bearings are failing which causes high load on the resistor and it over heats. 

 

Doing any cheat will skip all this and typically result in pulling it later on because of other issues. Trust me after as many as I've done now it BEST to PULL the HVAC case and do a full service and cleaning. 

The heater treater part is good insurance. That little stepper motor is a pain to get to if the factory connector fails. 

Beer.

When things aren't cooperating.

I've done my heater core and @JAG1work truck heater core, heater treater, AC evaporator and accumulator.  I took my time doing  JAG's truck because we were also tearing the roof of my 5th wheel at the same time.  His truck took a day and a half with all the interruptions. 

Beer.....check√

I usually right around 6 to 8 hours to tear down and reinstall the HVAC case. Typically can be done in a day. Just take the time to look at everything. 

8 hours ago, IBMobile said:

I've done my heater core and @JAG1work truck heater core, heater treater, AC evaporator and accumulator.  I took my time doing  JAG's truck because we were also tearing the roof of my 5th wheel at the same time.  His truck took a day and a half with all the interruptions. 

Mostly coffee breaks, the rest was handing me tools up to the roof .

Edited September 23, 20204 yr by JAG1

No worse the all day affair doing a window motor in my truck door. 

Edited September 23, 20204 yr by JAG1

 Not looking forward to the job but I am looking forward to having good heat this winter. I'll do some more work on the a/c later. Have to replace the orfice tube, drier and check some o-rings. It has a very slow leak.

 

You may order one of the foam kits for them air handler box. Mine was all but gone on everything but the heater door. The evap is in front of the heater core and usually take the brunt of the dirt. I have been working on something as a filter to prevent some of the dirt/hair/crud that builds up in the core. 

 

Geno sells a set that goes in the cowl, that's kinda my idea.

 

Also, my new heater and evap core didnt come fully sealed off like the factory units. I used some weather stripping foam to seal around them.

Edited September 23, 20204 yr by That Guy

 I was planning on having to replace some seals or "weather stripping" when I'm in there.

 A filter would be a great idea to try to keep some of the crud out of the hvac system. 

I think I'm going to put some window screen over the recirc door in the cab and do the genos filters for outside. I thought on it for 3 days trying to figure out where to feasibly put a filter...... I couldn't find a place with enough clearance except external.

Won't work. For one there is large drain holes on the cowl that will draw in air. The cowl filters don't capture fine dist just large debris. Like I gleen this knowledge from watching older gent in Rhode Island try and keep mice out of his truck. The biggest entry is the HVAC case to the cowl. He was stuffing stainless pot scrubbers in every hole he could. 

 

There is just no way to keeping the debris and dust out of the system. The only thing I can suggest is run MAX A/C when your running dirt roads or super dusty conditions. 

Would it be feasible to maybe add a switch to close the door from outside air? Same as MAX a/c but by a separate switch, toggle or otherwise on the dash?

Vacuum controlled. The door motor is on the passenger side near the kick panel you might see it. You would have to apply vacuum to the side that pulls the door closed.

 Your right, totally forgot they were vacuum controlled 

 Finished the heater core replacement today for the most part. It went well, I was not overly meticulous with everything but I did clean things up. Wish I would have taken some pics but I was rolling along and didn't want to stop to go get my phone from the house.

 The evap core was almost completely clogged with dirt/dust and other goop. The heater core was definitely showing signs of leaking. Both have been replaced now, heat blows nice and hot (topped out my 125° thermometer) and much stronger now to.

 I have to vacuum the a/c tommorow and check for leaks before I charge it. 

 

That evap looks worse than mine, but par for the course.

 

I see heat vent temps in the 160-180 range.

 The thermometer I had in the vent is the one I use for a/c work, it tops out at 120 and it was pegged. I'm going to use my digital today and check it again just out of curiosity. Air flow is much better now. I may look into the filter setup from genoa, gonna have to wait a bit though. I'm laid off again for 2 weeks. (End of week one now) so once I get back to work. It may be a Christmas present for myself. Lol

14 hours ago, Doubletrouble said:

 

 

This is why I say do the job right. Look at the evaporator its covered in debris. The heater core is showing signs of leaking too. See now you rebuilt the entire system and the heater works better and the A/C will be nice and cold to meet you in the spring of the year. Everyone of the evaporator I've pull range from lightly covered to densely covered faces. Anyways afterwards I always get comments about the better air flow and better heating and cooling performance. Hence why I will not suggest any heater core change out short cut. Not to mention there is no filter system to prevent that either. It would have to be a paper filter of some sort to stop all thje small particles sticking to the face like yours. Evaporator sweats and stay wet while the A/C or DEF is running. It will collect dust and debris then dries off later to hang on to it. Just best to pull everything servicing and clean like you did and move on for 5 to 7 years and do it again. 

Edited October 2, 20204 yr by Mopar1973Man