I got a 99 diesel....when i got it, the AC would work for about 15 mins at a time, then just stop. i'd turn it off, wait about5 mins, turn it back on and it would work. when i turned heat on i could smell that hte heater core was goin bad. now i got antifreeze leakin into the passenger floorboard. question is, when i replace the heater core, is there anything else i need to replace that could have been causing the AC to act like that?

 

I followed these instructions yesterday and I found only one step missing and I took some pics. I however forgot to get a pic of the unit out of the truck. Some pics aren't here, if you need pictures for the steps that don't have them, you should be taking this to the mechanic.....I forgot to circle things in the pics, I will throw down with some MSPAINT soon to have the parts stand out.

1) Disconnect battery cable

2) Remove first screw on door sill both sides ( these are the pieces that hold your carpet down)

3) Remove kick panels and panel under steering wheel.

4) Remove two nuts holding up steering wheel.

5) Remove five screws where dash meets the windsheild.

6) Remove 2 bolts on the left and right side of the dash up against the side of truck (under kick panels)

7)Dashboard can now be pulled free toward seat.

8)On passenger side of dash tie rope or wire to flange where bolt went into side of truck and lift dash up
to expose fan box. Secure rope to handle on side of A-post


9) Remove vaccuum lines and unclip electrical connections. (Hint: temperature control cable has to be
removed with pliers by pulling straight up, removing the entire clip.)

10) Now the secret: there are two screws holding the box to the firewall on the inside (one has ground
wire attached.) The other is in the upper right hand corner facing up.


11)There are four nuts holding it from the engine side of the firewall (one nut is accessed by removing the
electircal panel on passenger side.) Remove all four nuts.

12)Remove heater hoses by removing clamps. Mine were stuck so I just cut the hoses and got new ones.

13)Release A/C freon from LP side with gages and disconnect A/C lines from firewall exit. ( This
requires a simple 5 dollar tool that disconnects fueland A/C connections.

14) The heater box will now come free!

15) There are several screws holding heater box together. It will come apart in two halves. Go ahead
and replace your heater core because you dont want to do this again in a month!

16) You may want to replace your accumulator as well (its fairly cheap)

17) Reassemble /reinstall box. Draw vaccuum on A/C system for 30 mins. recharge with 134a.


***All pictures are located here: http://heandshe.org/koldkut/Dodgeforum/HeaterCore/
My brothers webspace addressing has changed and the old pictures were not showing up. They are not in numerical order,Giv me a few days to get the files renamed in order so that they may be put with the direction numbers. Thanks.***

 

I wish I had search for this yesterday.[:@] Oh well, the aluminum replacement heater core from O'Reilly is crap. I don't trust it as the inlet/outlet pipes rotate. I'm getting a copper/brass replacement from Rock Auto. I bookmarked this. Thanks to Koldcut for the pics. The 97 is slightly different (no handle on the A pillar), but that's about all.

 

man you guys are awesome for throwin this post up here thanks for the details i was sweatin this crap.......but i do have one question, seeing that I am simply just replacing the heater core and not the A/C evap, do I HAVE to discharge the a/c? or is there some way to remove the heater core by itself w/o pulling the whole thing out? maybe cutting the box or something then JB'ing back together? cause im scared to mess with the A/C system and my local shop wants $150 freakin dollars just to discharge my system for me ><, thanks again guys

 

I removed the two large clips on the accumulator and managed to pull the box back far enough inside the cab to remove the heater core. I STRONGLY recommend you have an assistant when you do that and especially when you re-insert the heater core.

 

ok i think illoffer my neighbor some beer to helpme hold it in place and takea stab at it first thing tomorrow thanks for the info guys ill let ya know how it turns out.. nice avatar by the way too many problems to circle......

 

Thanks for the pics Koldkut. I should have put them on the original. I am glad it worked out for you as well. I really didnt think it was all that bad. As for removing the heater core without unhooking the evap... ( I dont see it happening at all, but maybe you can do something I dont know about)

 

It can be done, but it requires holding your tongue *just so* and massive amounts of swearing. I will post pics of what mine looks like.
*EDIT*

Here you go:

 

OK, got my heater core from Rock Auto (http://www.rockauto.com) and it is the exact match to the OE core. It's copper/brass wrapped in foam. I got some foam from a local hobby store to replace the piece that goes between the core pipes and the firewall. Here is what the new setup looks like:

 

i have the exact same question. i would prefer not to discharge the A/C system if i don't have to.