[MarineJRM]

I just want to add my 2 cents on this and see if I might be able to save someone else some heart ache. I did my Evap Core and Heater core yesterday. Took me about 3Hrs to get to putting it back together. Got it back together in no time and the vents werent working properly. After messing with this controls for about 20 mins I figured I didnt hook up a vac line on the HVAC box or I had damaged the actuator for the blend door (I had flames for heat). So I took the time to completely take the dash apart again and found nothing wrong. After wanting to torch the thing I went to smoke a cigarette while the truck was running and I heard a hissing noise. Vac Line capow strike of lightning. I traced it down to where I had just put a Nates 4x4 bumper on and took the damn little ball reservoir off and left the vac line like an idiot. Turns out that vac line runs you HVAC vents. If you have installed an after market bumper and didnt have A/C when you baught the Jeep just remember to hook that ball back up and avoid a huge head ache.


6 Hrs on the job =

Cold A/C in flaming hot heat = Priceless

Good Luck on the job

[JoBo]

I'll add my two cents too. My old evaporator had a filter like piece installed over it and there were 5 plastic clips driven in between the fins holding it. From the dye I had put in it was clear that my leak was caused by one of those plastic clips. So needless to say it was not put on the new evaporator.

[MarineJRM]

That sucks I put those clips back in. And looking at my old one the green dye was around one of the clips

Here are a couple of links for those of you looking to do this.

Quality ACDelco Evap Core Made in USA Not China

97+ Cherokee

Rightnowautoparts.com

Proliance Heater Core a good bit more heavy duty than the lil OEM one.

Rightnowautoparts.com

Saving money is always good stuff

[GregB_00XJ]

Excellent write up and pics!! I am lucky enough to get to do this job sometime soon. Will be stockpiling parts, and will go the new Evap Core as well as Heater Core (just on case).

I had to do this on an 87 Ford Mustang LX... same shiz different maker. It took me 8 hours total as someone else dismantled it for a friend, and bailed on her.

Not looking forward to this, but with this write up I am nowhere as leary of attacking it.

Thanks!

[JoBo]

OK THREE CENTS worth this time. The larger heater hose is 11/16" and NOT 3/4" That might be why people are having leaks at at the firewall with that hose because they are putting on bulk 3/4" hose.
The cut rate chain parts stores like Advanced Autoparts and Auto Zone only list the shorter heater hose that's 5/8" for the 4.0L XJ
NAPA has them both of them.

[dennisM83]

Thanks for the write up and plenty of photos! This has immensely helped me.

I know this is old, but maybe someone could answer a silly question for me. When I pulled the heater assembly apart, this plastic piece fell into the lower half, so I'm guessing it goes back in the upper part. Any ideas where?

http://i20.photobucket.com/albums/b244/ACeZ83/carstuff/misc003-1.jpg

EDIT: I think it goes where I put it in the photo below. Is it correct?

http://i20.photobucket.com/albums/b244/ACeZ83/carstuff/box.jpg

[jsmiddleton4]

Well the quick connect is not leaking. I have a leak in the exchanger core in the heat/ac box under the dash. Have been fighting pulling the box due to another issue and now I guess its settled. I have found a box at the local Jeep only junk yard for 50 bucks. Going to rebuild it at my leisure and then when we drop the dash its a swap rather than a drop, see what needs to be repaired in terms of flap doors, etc., track down those parts, and then put dash back together when the box/cores rebuild done.

I've PM'd Mort to get source list he used for his cores, new motor, etc.

Have until end of April beginning of May to get ready for the heat here in AZ.

The shop that did the leak detection for me wants near 1400 to do the job.

[jsmiddleton4]

XJ Guy...

I'm getting ready to do this job as well. My AC evap is leaking. Do you still have a parts list/supplier list? Like where you got the motor from, etc. I understand the foam gasket kit is a dealer item.

I need the heater core, ac core, foam gasket kit, want to replace blower motor and accumulator.

Not sure about the line fixed expansion valve thing....

[jsmiddleton4]

Have found everything here save the dealer only foam gaskets.

Jeep air conditioning components and complete A/C kits for all Jeeps

Still working on thinking through each step. How do you check the heater core for leaks prior to full assembly? Seems like there has to be a way. I was thinking adapter and use water pressure from a garden hose.

Picking up the heater box to rebuild Tuesday. Will make it so much quicker when we drop the dash to have the "new" box to swap back in.

Does the foam kit from the dealer include the foam inserts for the heater/ac cores for inside the box?

How does one test the vacuum motors and not blow out their diagphrams?

Feeling like Columbo here.....

[JoBo]

City water pressure might cause a leak. Normal pressure determined by the pressure cap is under 20# and city water pressure will be more then that for sure.

[jsmiddleton4]

So don't completely stop the water return to keep pressure from getting too high?

[jsmiddleton4]

And today, my journey begins. Will be April/May before I drop the dash however. I picked up box in pretty good shape at Jeep junkyard for 50 bucks. Its heater core must've had slow leak.

Has one minor problem on the top piece.



The internal part of the axle housing is fine, the base of the housing/hub is fine. The flap works without binding. Not 100% confident in it of course. The top piece of the one currently in my 1997 does not seem to have a problem so its possible I can use the one in my Jeep. Also IF this isn't really a big deal, I'll not do anything. I need to take the top off and see inside to see how strong the hub is with this outer end part cracked.

Fixes?

Will rebuild it and then when I do swap won't take so long to start reassembly.

[kowboydmac]

Any updates around..? I'm currently in the process of mine. Had ot leave the dash taken apart over night, well get to it this afternoon and pre-super bowl

[Greenz]

Originally Posted by jsmiddleton4

How do you check the heater core for leaks prior to full assembly?

How does one test the vacuum motors and not blow out their diagphrams?

Feeling like Columbo here.....

When I did mine last summer I just hooked up the heater core external of the box. I just let it dange from the hoses. Fired up the jeep and let it run a good 20 mins. I too wanted to know for sure there were no leaks before installing.

I used a hand operated vacuum pump to check each door function. Then I attached the dash panel control switch to the box, pumped up the whole assembly and tested all door functions with control switch. I did all that in the garage with the hand pump, but you could run a vacuum line from a running engine.

[JoBo]

Another thing you should be aware of
The hoses are different sizes and one is 11/16" and if you use 3/4" you'll have trouble getting it to stop leaking and it could run inside making you think you have a leaky core Last summer when I did my evaporator and heater core I also put on new hoses. I found that Advanced Autoparts does not have listings for both hoses, only the larger 3/4" one.
I was able to get them both from NAPA

JSmiddleton.

I would put a spring type hose clamp over the cracked hub.