Heater Core replacement tips?

[79BIG10]

Well on the way to work today (even though the heater wasn't on) I noticed that sweet smell and saw a tiny drip on the passenger side starting to begin. I saw that the heater core is starting to leak so time to replace ASAP. I saw the articles here http://coloradok5.com/heatercore.shtml but was wondering if anyone else had more tips on this. I've already changed out the antifreeze and radiator cap (I'll replace the hoses while I'm there and the core is out) but need to find out if anything else I might want to change while I'm there.

[rolson1039]

do you have AC or no?

[jakeslim]

its not a bad job, just not as quick as changing plugs. I used the same article and had no issues. Just take your time and don't expect to finish in an hour and you'll be fine.

jakeslim

[79BIG10]

Originally Posted by rolson1039

do you have AC or no?

Yes I do but it's not hooked up. The firewall etc. has the AC hookups but when the original engine was worn out I took it all out since it was full of leaks etc.


jakeslim- Thanks for the heads up. I was thinking it was going to take about 4 hours to be safe. I'm going to replace all I can while I'm there as well.

[ChadM89]

I just replaced the heater core in my '84 K10 last week.

I have a Haynes and Chilton manual and neither of them said anything about the 3 captive bolts, so that came as a surprise to me. Getting to the two on the bottom was a pain in the ass but I got 'em.

After unscrewing the rest of the connectors and unhooking the cables for the top of the box, I pulled it out and took it to my workstation.

This is when I encountered the most frustration.

There's a vacuum thingy on it (one of two), which is attached with a bolt INSIDE the box, so I had to bend the crap out of the box to fit a socket down inside and get it loose. I thought I was home free once that was done but I couldn't have been more wrong. There's a rod that goes all the way through the box and it's what the heater door swivels on. The way they built it, I could see no way of getting it apart at all. I eventually took a hacksaw and cut a path into the box for the piece of metal on the end of the rod to travel through. It literally only takes like 20 seconds to replace the core itself, then I started putting things back together. I re-assembled the box (once again wrestling with that stupid vacuum thing) and then I used some insulating tape to seal up the box where I had cut it to get it apart. Re-installed the box and the heater works like a charm.

[SanitysBane]

it helps a ton to pull the glove box out to get to the cables and such on top

[gn4u2c]

Wow I just did mine last night 85 with air took about 1hr total ..the bolts/stud nuts outside on the bottom of the box 12 " extension,swivel,3" extension then socket they came right out. the top stud is easy to get to, hoses (replace them while your at it)and the bolt inside not much at all 1 bolt holds the cable to the bracket, 3-4 8mm for the duct work mounts. and the box is on the floor flip it over pull the first 6 6.5 mm 2 are under the seal you may not see them at first leave the others in it will pull apart enough to get the 2 that hold the core clamp on the other side just slides in reinstall same manner.
I have seen people do this job and take the box off the firewall out side ?? why . just asking to cause a leak in the seal and make it tuff to get the core inlet/outlet though and all lined up.
fill the system up with new 50/50 mix and go.
If anyone is close to me and want this done. I will do it for a case of beer

[gn4u2c]

You supply parts

[79BIG10]

I got mine out but it was a PITA!! The hard part was the speed nuts that would not come off for anything. I used a long extension and dropped the inner fender and still couldn't get it off. So out came the dremel and new bolts and nuts. I replaced the hoses while I was there and cleaned us some stuff. The only other problem I had was the vacuum port on the top. The line broke off but was able to repair it enough to get by.

[Gray Ghost]

Sorry but after just doing mine with a lot of help, I do not believe anyone can do it in one hour...unless of course you have no fenders, dash or AC box in the way, or you have done it professionally more than a few times.

What a pain in the arse. Has to be the most moronic design I've seen on any part of any vehicle.

[apstguy]

I Took the thing out in an hour but It took me about 3 hours total because I also cleaned the whole thing out and lubricated all the doors and such. The top speed nuts were broken off the box so only the lower 3 are holding the damn thing on! I think I might need to replace it again - That will teach me from using a kragen heater core.

[gn4u2c]

Bring it over . It's easy when you work on alot a cars and have good knowledge and all the tools you need organized in a good box. Alot of people waste 1/2 the time they spend working on stuff searching for the correct socket or swivel or whatever.
Not being as ass or anything and i will help anyone do theres if they like. Yes you can time me.