Hiya Fellas!.....guess I'm the new kid on the block with an older model Sierra. Trucks are totally new to me but working on my own vehicles is not. I've just become the new owner of an '82 C/K 1500 Sierra Classic. As little as I know about trucks I think this ol gal has a lot of life left in her. She just needs a little TLC.

My immediate problem is this. When I turned on the heater and blower. The blower came on fine but nothing coming out from the defroster. That led me to think the duct had a flapper that was not working. (revelation)Hmmmm, maybe that's why someone took the glovebox out. I was able to find the right flapper and sure enough it was in a closed position. I followed what looked like the same process as the previous owner and took a piece of wire and propped the flapper in the "open" position". Nowwe had air coming out the defroster but no heat. So I pulled the thermostat housing and voila! No thermostat. So I go install one and top off the coolant and things seemed ok last night. I went to drive about 40 miles this morning and all the sudden coolant came pouring from under the heater duct. (another relevation) Hmmmm, maybe that's why there's no carpet or padding on the floor. I finish my round trip with no problems. I would guess I lost about a few pints of coolant. So I get back into town. Stop for about 30 mins. Drive about 3 blocks and the temp is starting to peg out. 3 blocks more and it's back to 1/2 way on the gauge where it should be. When it pegs out on the gauge there is no heat. After sitting about 30 mins I drove it 5 miles to work without incident but coming home it was back and forth from pegging out to normal. I still have not replaced the coolant that was lost earlier today.

Am I looking at a new heater core? .... or maybe just a hose to the core?.......Are these a pain to replace? Any thoghts and tips would be greatly appreciated!!

Nice to meet you all and hope to hear from you soon as it's gettin cold and the rear sliding window is missing and I have yet to replace that too.......Brrrrrrrr~!~

 

By the way, Does anyone know where I can find the GM part# for this heater core?

 

OK, well even though no one responded I found the part. Has anone ever replaced one of these themselves? What all is involved? Thanks in advance!