99 Jimmy heater core "How do you open the box?"

[gemkindagirl]

My husband and I spent all day taking the dash apart in my 99 GMC Jimmy to get to the heater core. We had the black box sitting right in front of us and couldn't get it open. We looked for every bolt and let me tell you some are hidden well. The box would move but it would not open. Does anyone know of some "secret" bolts holding it from the firewall side or is there a trick that we just don't know about? Any help would be greatly appreciated. All the books show pictures and give directions for the 97 and earlier models and they are completely different . I have not been able to find any information on this for a 99 model and every forum I have checked is very vague. Someone said there are two to four bolts in the firewall that have to come out. Well I would like to know how many is it? Two or Four? It makes a big difference and where if these bolts exist are they located because we can't find anything. All information is greatly appreciated. I want to have my ducks in a row before I take the dash out again. That heater core is going in if it's the last thing I do. Thanks all!

P.S. I have pictures if anyone wants them and if anyone needs to know how the dash comes out I can let you know. We figured it out the hard way.

[convertz]

If its anything like my 2000 Blazer was there are about 5 bolts on the firewall side. There is one stud to the right of where the hoses pass through. There are two under the AC box, using the same bracket as the heat sheild over the exhaust manifold, there accessible from the wheel well and I destroyed the heat shield to get to them. One is around the rubbery AC box cover to the left of where the coolant lines go through. And the one that is rough to find is inside the AC box on the right side when ur facing the back of the car. There is a line that has an arrow pointing to it that says cut here for service. Under that rubber flap is a plastic plate held down by 3 screws. Take that off and theres a bolt night next to the evaporator coil. Good luck with a bunch of swivels and extensions, and not dropping that bolt.

I have a few pictures of this stuff, email me at [email protected] of you want em

[photohawk58]

Hi Gemkinagirl, I would be very interested in seeing any pictures of how to take a dash out, and any info. I have 99 Jimmy and am very scared my heater core could go soon. I had a 93 jimmy and with al it's proper matainance the heater core went twice, every time almost 5 year to the date of replacement. Tell me that isn't a designed core. You can e-mail me at [email protected]. Anything about this would be greatly appreciated. Truthfully I am almost ready to have my 93 completly restores and put it back on the road because I am just about feed up with this 99. I have had brake problems, Intake (anitfreeze) gasket leak problems, oil cooler lines leaking, the gas mileage is really bad. I just wish I could just take the body and set in on the old one, ha,ha .

Thanks,
Photohawk
PS: here is another good foum group, for information, the GM guys are pretty good here.

http://groups.msn.com/AutoTechsOnline

[rlith]

The haynes manual actually has a decent how-to on removal of the 98+ heater cores. But as said, there are some screws on the firewall side that have to be removed to pull the core.