New to group: Thanks for any help anyone can offer. Have a 90 suburban just bought and am repairing. Has a leaking heater core. Searched the repair manuals, but not very helpful. Just need to basic steps to get to core. Appears to me that the evaporator cover under the hood has to be removed to get to the nuts that hold the case on under the dash. Can't find a way to get to it just from the inside. Do I have to disconnect the AC system in this process? Have several other problems, but want to take them one at a time.[sm=feedback.gif]

 

I had to do this on my 87 as well..... to my recollection yes the box on the outside needs to come off to get to it, but the nuts are on the inside of the firewall, this is a very unfun procedure. Unfortunately it has been about 5 years since I did that and I cannot remember if I disconected my AC for that or if it was for another repair I was doing??? Sorry, I know its not alot fo help..

 

no u don't need 2 touch the A/C 2 remove the heater core box (just did mine on my '90 'burb in July)

***** be XTRA careful when u split the box open 2 remove the core***** the pivot pin that holds the directional door in place (& controls the direction of the door), needs 2 b removed carefull, as the small brace inside (that is part of the box, therefor made of plastic & brittle), will snap off so easily if u try 2 force the pin out. take your time & spray some WD on it, 2 help it slide out easier. good luck.

 

Does the evaporator box in the engine compartment need to come off to get to the nuts for the core box? Thanks for the info.

 

Well got it out and am well on the way to putting it back together. Plastic cable holder broke because the last person who worked on it over tightened it and cracked it so that when I removed the screw it just fell apart. Going to use a couple of zip ties to hold it in place. Also the end twisted off of one of the fire wall studs due to the stud part being bent. Plenty of stud left to push through firewall and put on new nut. Glad I didn't have to take the evaporator box apart that is located in the engine compartment. If anyone needs advice on the job, just let me know. Not as hard as some jobs I've done, but did take the better part of an afternoon. [sm=patriot.gif][sm=americanasmiley.gif][sm=icon_rtfm.gif]

 

[QUOTE=usmc2037;14007]Well got it out and am well on the way to putting it back together. Plastic cable holder broke because the last person who worked on it over tightened it and cracked it so that when I removed the screw it just fell apart. Going to use a couple of zip ties to hold it in place. Also the end twisted off of one of the fire wall studs due to the stud part being bent. Plenty of stud left to push through firewall and put on new nut. Glad I didn't have to take the evaporator box apart that is located in the engine compartment. If anyone needs advice on the job, just let me know. Not as hard as some jobs I've done, but did take the better part of an afternoon.

im about to take on my own heater core this weekend on my 1991 R1500. Any advice/tips/videos you’d recommend before tackling the job? I have a good idea of what needs to happen just looking for any clarification or tips you have. Thanks in advance!