Heater Core Servicing

[Mopar1973Man]

I want to bring your attention to heat core servicing. I know there is a thread over on CF explaining on how to do the short cut method where you cut the tube ends and hose clamp inside the truck. This gets around the idea of having to recharge the A/C. I would like to advise against this method being so far the HVAC I've open in the years all them are truly funky looking with everything from mice nest to like this one with packed hay and road dust. If you going to do a heat core do it right and take care of everything. This includes the stepper motor for the blend door, dust and debris on the system, check your blower motor for problem and resistor.

[CTcummins24V]

Mike, could you make a full list of things to replace while the dash is apart? Best to do it once and be done with it.

Come spring time, I'm going to install my new LMC dash and replace the AC evaporator and heater core. Add blower motor to that and blow motor resistor and...and something dripley mentioned in another thread?

-AC evap

-Heater core

-Blower motor and resistor

[dripley]

The Heater Treater thing for the blend door maybe?

[Mopar1973Man]

That's about it right there. Nothing really left.

[dripley]

One thing I ran into when doing mine was the foam gaskets were in rough shape. I bought some similar foam at the building supply and cut it to fit . Everything still seems to be working fine, Not a real good way to check on it. As long as all is working good I guess the home made gaskets are holding, 

[Mopar1973Man]

I typically use canopy weather stripping for resealing the evaporator which works pretty well. Heater core can use some too but pretty thin stuff.

[dripley]

I used multiple kinds just don't remember what. Just looked at what was in there and bought the closest to it I could find.

[Hawkez]

Does the dash have to come out to get all of this out?  Are you able to clean this heater core up, or are the cheap enough just to replace?

[CTcummins24V]

Heater core is only $135. Might as well replace it, I believe they corrode from the inside out, so best to just replace it. 

[Wild and Free]

Dash must come out and If going that far I would never reuse a modern aluminum heater core for the amount of work it takes to get in and out. Replace it and forget it for another 200K.

[Mopar1973Man]

If your going to get to the point of doing the heater core you might well service the entire HVAC box and know everything works correctly.

 

[dripley]

Do it all and be done with it. 

 

 

 

[Mopar1973Man]

I started today by washing out the entire HVAC case with a power washer and 40* nozzle. Glad I did this because the stench of dried antifreeze would have stayed in the box. Every time the owner would fire up would smell antifreeze old antifreeze. That's gone now with the washing. The evaporator got a good washing out externally and the mud ran out of the face. Much better you can see light through the evaporator now. Now I get to the blend door stepper motor and find the plastic bushing is cracked. A good time to just order the "Heater Treater" and replace it.

 

Edited December 24, 2015 by Mopar1973Man

[John T]

I just finished mine today. one thing I might add is this: 

I spent a whole day looking for the plastic snap- in nuts at the front of the dash. all of mine were broken and I ended gluing them in with Gorilla brand construction adhesive. I found out later, Geno's garage sell them but they are almost $6 each. I don't know which model years included these nuts but if I had them on hand it would have saved a lot of time and frustration.   Did I mention they are almost $6 each?

[Mopar1973Man]

I found on this truck the dash cracking issues is from the driver side kick panel bolt was loose so the entire driver side is cracked from loose bolt from bouncing around the back country.

[dripley]

Mine just cracked all over. It started from one of the screws at the windshield came across and then started from another one and they just started connecting with each other. When I bought my LMC dash I also got the washers they recommended. Not sure they were going to do any good, but bought them any way for insurance. They are supposed to spread the load on the holes for the screws. Only time is going to tell on them anyway. 

[catnhat]

I need to do this to to my 97.i just don't want to crack a perfect dash