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Stock XJ Cherokee Tech. All XJ Non-modified/stock questions go hereXJ (84-01)
All OEM related XJ specific tech. Examples, no start, general maintenance or anything that's stock.
I'm going to need to do this job in the spring since my evaporator leak has gotten worse. Although taking the seats out will make more room it's a problem for those of us in the salt belt. The seat bolts are invariably rusted solid. I'm definitely doing the heater core as well while in there. I'd like to go with a copper heater core when the time comes but the only one I've found so far is a bit pricey. (Currently out of stock, it seems to be a small company that periodically makes batches of them every few months.)
Credit and appreciation must be given to the authors of these procedures, they spent a lot of time writing everything out and taking photos. I am sure these docs gave many the confidence to replace their own heater and evap cores.
The first PDF file is the one I have ...it helped me out a lot.
NCDON, thanks for providing the pdf and link. The heater core and evap instructions were great. I wish I would have seen this before since I had detached the vacuum lines from the box and it looks like I could have kept them on the box.
I'm going to need to do this job in the spring since my evaporator leak has gotten worse. Although taking the seats out will make more room it's a problem for those of us in the salt belt. The seat bolts are invariably rusted solid. I'm definitely doing the heater core as well while in there. I'd like to go with a copper heater core when the time comes but the only one I've found so far is a bit pricey. (Currently out of stock, it seems to be a small company that periodically makes batches of them every few months.)
You don't have to pull out the whole seat track assembly from the floor. You could remove just the seats. They are attached to the tracks with four 13mm flanged nuts on M8 studs.
Do you guys know if the foam and stuff for the heater core and evap need to be rated for high temperature? I'm trying to replace all of these seals and such with stuff from home depot or even some leftover foam from Amazon packaging to make my own seals. I'm not sure what sort of temps the HVAC box will be exposed to.
I picked up this closed cell peel and stick at Lowes in three different sizes (see packages) and will use it unless someone else has a better idea, see dimensions on packages.
The jeep thermostat is 195F, using a hand held pyrometer on a hot summer day I've recorded the thermostat housing at 210F so I suppose the heater core would see this temperature. No idea how the adhesive on this foam or this foam will react to this temperature.
NCDON, too funny. I bought some of the same stuff today and used it in various places.
Got the HVAC box in, dash connected with one bolt and the new heater hoses connected. I'm going to wait until tomorrow to fire it up. I'd rather not now if it doesn't work tonight.
I'll update in the morning on whether it works ok.
The way to go is the McMaster Carr foam. Do a couple Google searches, for 'XJ heater replacement foam' and there some forum how-to posts. Guys have links and part numbers. That's what I did. It's basically the same thing. And use a good spray adhesive to put on. But yeah, you could probably use thin home center foam too. The thin spongy stuff. I don't see any reason it wouldn't work. Just need it where the door meets the housing. If you want to go cheap, go the Home Store foam route. If you want to do it like OEM, the McMaster Carr foam is the way to go. It won't be anywhere near as cheap. I probably spent $30-$40 on McMaster foam by the time ya figure shipping and minimum size ...and still have too much left over. ha ha..
Another route for thin foam for like the flapper door would be to buy a small piece of headliner from a fabric store that has the black foam backing ...and peel away the fabric. Then you get the foam you need and no shipping costs. But it won't be the thicker stuff (if you need that).
Just don't use like the white foam you see at a craft store. It doesn't stand up to age well and it'll get brittle and crumbly fairly quick compared to the black foam. Maybe other people have ideas that they used.
Last edited by Jeepwalker; 10-12-2019 at 07:09 PM.
I posted in another thread but thought I would update here as well.
Well, I had everything connected and I had leaking coolant in the cabin and no hot air. Guess I'll be taking it out again . Man, I really want this job done.
Good news on the leaky heater core replacement. I got some advice on another thread and they said to make sure I had the heater hoses tight and lined up good. We I readjusted and tightened and no leaks!! I'll run it again tomorrow to confirm but looks like it is ok!
Yesterday I removed my air box and disassembled. The heater core shows the telltale signs of leakage in several areas, the AC evaporator core had some of the leak detection die on it confirming it also was leaking
In my quest to have my existing copper/brass heater core recored. I visited two old school radiator shops that do radiator recore work but they were not able to find a supplier that has the replacement copper core for my existing heater core. One of the shops did find a supplier that claims they have a new copper heater core, the shop ordered it but I suspect it will be an aluminum core when it arrives, but who knows I could get lucky.
As a backup, I had ordered from Amazon and received a Spectra Premium heater core, it arrived damaged, the core is visually twisted so I shipped it back for a replacement. The shipping box the heater core shipped in arrived in good condition but on reinspection I can tell that other boxes were stacked on top of it, this may allow the box to deform slightly damaging the heater core, I have to question how many cores are damaged slightly in shipping stressing or breaking the core reducing product life. Amazon is shipping a replacement that I will use as a last resort, I hope it doesn't arrive damaged.
Well the good news is I don't have a pressing need for the jeep right now and can afford the downtime.
That radiator shop is probably correct: You can get a new copper heater core for some XJ's. I bought one last year. Look up some posts I made in about Jan or Feb, I don't remember the mfgr name ...Vista Pro, I think. The company sells through dealers like radiator shops. If they 'REALLY wanted to sell a lot more, they'd actually try to advertise. Good quality unit. See if you can return it if it shows up aluminum. It actually seems to have MORE heating surface area like it may be sized as a High-capacity heater core (for cold weather climates). Yes, it has fewer water passages, but they're fluted in a way so if you stretched them out they'd be 20% longer than the core length ...plus more copper fins and they're distorted so air will pick up more heat from them. The new copper core didn't fit into the stock foam surround perfecly, but the foam on mine was pretty deteriorated so I discarded it. They send along a piece of 2" wide self-adhesive foam and I used that and it seals well. The aluminum core may fit in the original foam surround better. I had both aluminum and copper and went with the copper in the end. I'm sure the aluminum core will work fine too.
Flush your coolant first so you don't pump a lot of garbage into the new H/C ...and also use purified water (not Tap water) ...I'm sure you knew that anyway, just throwing it out for other readers in the future. I would personally tweak your coolant's pH, or at least read up to it so your core doesn't become a sacrificial anode! ha ha.
Mine heats like a mother!
Crown vs Vista-Pro
Last edited by Jeepwalker; 10-17-2019 at 01:20 PM.
10-10-2019, 11:53 PM
