Heater Plenum Issue

[Topzide]

On my '01 1500, I laid the column on the seat when I pulled the dash to replace A/C evaporator and heater core. Did it with help of a Haynes manual. Wasn't to bad to do on my own. Chock your wheels when laying down the column as well as e-brake engaged! Ask me how I know that one! May want to see about adding a cabin air filter while in there to help in catching any debris that can get into the air box and rot out the A/C and heater cores! Wish I'd done it on mine. Only PIA was the bolt to HVAC box that went through firewall that stripped the mount on box and now rattles on high fan. So far they doors all work but I think compressor has given up. Just a plow and emergency back-up vehicle now.

 

[Mike Wenrich]

Thanks for the link to the manual. I need to save that link for use other than this one. Really good to see the pictures and process. I'm good using pictures. One thing I don't see and the next post by Topzide mentions the bolt thru the firewall. Watching a video of the replacement of the unit the mechanic mentions the need to remove the ECM to get to the nuts behind it. I don't see mention of this in the manual. Appears there are nuts on those bolts. So maybe there are different methods used by Dodge to secure the plenum.

 

[bcbender]

I don't recall if I had to remove it, but Topzide's truck is an 01 and yours 03 so they are different bodies and layouts from 2cnd to 3rd gen.

 

[Mike Wenrich]

Yes I will be working on 2003 and 2004.5, both dual zone. But I believe the manual link is for 2003 and it shows nuts to remove/secure the plenum. I will know more when I get in there. Need to get these kits ordered and after the good reviews re: this issue have decided to go with the Blend Door kits. Either is probably good given the age of these trucks and my age BTW but I sure don't want to have to go back in there.

 

[Topzide]

I think they all have a bolt or two through the firewall. Look and find them, clean threads and spray with something to help with the nut to come off the stud. Even through different gen, still same principle of work that needs to be done. If I ever have to go back in there, , new everything again and a new dash top also!

 

[CharlesinGA]

There are excellent videos on Youtube for doing this, they are expertly scripted and well organized. Impressed me enough to capture and save them. My truck had the doors replaced early on, almost for certain with OEM doors, I may just stock the Blend Doors USA set just to have them in case.............

Part 1 Removal of unit from truck................. youtu.be/dBAtCnIxC2A
Part 2 Replacement of damper doors............. youtu.be/_sRvLSDALLc
Part 3 Unit reinstallation in truck.................... youtu.be/sN9VUyZzLKg
Part 4 Mega Cab damper replacement............. youtu.be/G-Ri_XFdREk

I had to delete the https:// from the URLs to prevent the forum software from converting the list to media, in case you want to make a word processor file like I did with the info in it.

Part 1 Removal of unit from truck

Part 2 Replacement of damper doors

Part 3 Unit reinstallation in truck

Part 4 Mega Cab damper replacement

Videos are produced by https://www.youtube.com/user/flopster843/videos

Which is CarboniteCummins.com

Charles

 

[Mike Wenrich]

The second video is very informative with the rebuild inside the box and how the whole thing works. Thanks for adding to my knowledge of this unit. I will save these as well. I have one helper lined up for the first one but won't know if I want to just lift and bend/move the dash back to remove the box or lift it over the steering wheel and take it out of the truck. Depends on how much room I have I suppose. This mechanic makes it look easy to move it back but I think I will lose a quart of blood trying that. Doors are on the way and I'm hoping I don't have to change the evaporator or heater core. That will mean a delay due to getting parts.

 

[Rowdy Dalton]

The second video is very informative with the rebuild inside the box and how the whole thing works. Thanks for adding to my knowledge of this unit. I will save these as well. I have one helper lined up for the first one but won't know if I want to just lift and bend/move the dash back to remove the box or lift it over the steering wheel and take it out of the truck. Depends on how much room I have I suppose. This mechanic makes it look easy to move it back but I think I will lose a quart of blood trying that. Doors are on the way and I'm hoping I don't have to change the evaporator or heater core. That will mean a delay due to getting parts.

Would it be the smart thing to replace the Evaporator and Heater Core, since everything will already be out in the open? I know my doors are on the verge of needing to be fixed, and with the truck being an 06, I think I will do those too. An ounce of prevention thing.

 

[Topzide]

@Rowdy Dalton, Since your already there, might as well do it. You know what could happen if you don't. Either way there could be a failure without notice. When I was in mine many moons ago in my 1500, I opted to replace both since evap was being done. Enough of a problem to pull apart in the first part, sure wouldn't want to have to go back in if it could have been avoided! Cheap insurance to just replace them while there. Just take the time to inspect and double check all connectors as you put back together. Good luck with the repairs!

 

[bcbender]

Its a personal thing,.. I have moved past replacing parts just "while you're in there...." I did my doors on my 04 around 120k.. checked the heater core, did NOT remove or disconnect the evaporator, but it looked OK.. Never had an issue in the 80k (7y) I drove it after that. But its a risk / reward thing, for me if components are in good shape and still have service life, no need to change.

 

[bigceltic]

Would it be the smart thing to replace the Evaporator and Heater Core, since everything will already be out in the open? I know my doors are on the verge of needing to be fixed, and with the truck being an 06, I think I will do those too. An ounce of prevention thing.

I had mine (Evap and Heater core) changed since the shop was already in there. Just peace of mind as I plan to keep my truck for the foreseeable future.

 

[Mike Wenrich]

I've been thinking about changing them as well but since I keep my anti freeze changed out on schedule I figure the heater core should be good. Unless of course there is some chemical in there that corrodes them. The evap is another story. With the constant pressure in there and exposure to dirt from the outside, which might apply to the heater core as well, maybe I should change it. Watching the videos the mechanics point out to inspect them but if no sign of leaks you should be okay. I plan to check with the local mechanic I use for some work and will be using him to disconnect the lines for me. Then he will recharge the system when I am done. I don't have the tool to do the disconnect. Then there is who do you buy from. If the evap parts are Chinese do you use those?

Sure don't want to do this twice. Still waiting for the blend doors to arrive. Coming by USPS Pony Express. On an old horse. Like me.

 

[bigceltic]

I also added a "cab fresh" filter to ensure the new evap stays nice and clean (I think this is the one: https://www.genosgarage.com/product/cff-dg-19003k/interior-replacement-parts)

 

[petersonj]

I also added a "cab fresh" filter to ensure the new evap stays nice and clean

A good move on your part. It is hard to believe that a cabin filter was never provided by the OEM. I installed the equivalent filter for a 2002 truck from Geno's. Plus, I fabricated a coarse screen for the blower fan outside air inlet.

I just did the same heater core and evaporator core replacement on my brother-in-law's 2002 Dodge Cummins about two months ago. I installed the same screen.

 

[Mike Wenrich]

Received the blend doors today and drained the radiator in prep for the job. Have a request though for thoughts on the molded heater hoses attached to the core. Besides the fact that on a diesel they will be harder to get them off the core I was thinking these are 20 years old. They feel and look great. Had I thought about this before I would have looked into general replacement due to age. But I'm not sure of the availability other than from a MOPAR parts source or even if I need to do these since they look so good. Tested the 5 year old anti freeze and it's as good as new as well.

I'm in a very rural area and we have no way to recycle anti freeze except for once per year at our landfill, wait for it...by appointment. And only a few (20) appts are available. I don't want to dump the stuff on my acreage and have it wind up in our water, etc. So I'm thinking about putting it back in. I'm asking what experience others might have had with the heater hoses and how long they run the 5 year HOAT. Perhaps it's good for a lot longer period. As well as the hoses if they are not cracked and dry.

 

[User113]

My heater hoses are still fine after 20 years. They don't make 'em like they used to. My hoses were hard to reach, but they came off quite easily.

 

[Mike Wenrich]

BTW, I spoke to a local mechanic who has had a shop here for many years and serviced a lot of heater cores. He mentioned if I thought about general replacement of the core to get a MOPAR unit. The aftermarket cores are not reliable. I have seen this same comment on a TJ Jeep forum. The factory cores are no longer available for the heater and the engine. I had a new aftermarket radiator put in mine and it leaked from a tank seam. He also said if you buy one from a parts store to pressurize it overnight to see if it's going to leak. Terrible what has happened to our parts chain.

 

[brucejohnson]

BTW, I spoke to a local mechanic who has had a shop here for many years and serviced a lot of heater cores. He mentioned if I thought about general replacement of the core to get a MOPAR unit. The aftermarket cores are not reliable. I have seen this same comment on a TJ Jeep forum. The factory cores are no longer available for the heater and the engine. I had a new aftermarket radiator put in mine and it leaked from a tank seam. He also said if you buy one from a parts store to pressurize it overnight to see if it's going to leak. Terrible what has happened to our parts chain.

Shows one heater core in stock here: https://www.moparwholesalestore.com/oem-parts/mopar-heater-core-68004228ab?c=Zz1haXItY29uZGl0aW9uaW5nLWFuZC1oZWF0ZXImcz1haXItY29uZGl0aW9uZXItYW5kLWhlYXRlci11bml0cyZsPTM2Jm49QXNzZW1ibGllcyBQYWdlJmE9ZG9kZ2Umbz1yYW0tMjUwMCZ5PTIwMDMmdD1zbHQmZT01LTlsLWw2LWRpZXNlbA==

 

[Mike Wenrich]

Thank you and good to know. Either mine or the neighbors might need this.

 

[Mike Wenrich]

Well, I hit a road block. Have removed all the nuts/bolts mentioned in the threads however I cannot get the dash to lift off. It moves up and down slightly on the driver side but almost nothing on the passenger side. And I did remove the one hidden nut. I have a Laramie and none of the videos show my exact dash but am I missing something? The steering column is down and I got the two hidden bolts behind that mounting plate. I removed the two on the floor beneath the ash tray/cup holder. The six below the window. I did not remove any of the screws holding the cup holder and the plastic facia above the floor bolts. Did not want to put too much force on it until I checked on suggestions. I cannot see anything keeping this dash from moving up but it's hard to see anything back there. Maybe I should take those out too? But the videos did not show that. Any thoughts appreciated.