Heater core replacement

[Rageous]

The core went on the M1009 antifreeze everywhere on passenger side.
How difficult is it to repalce the Heater Core, taking your time and trying to do a good job, how much time should I set aside for this project?

Thanks for your assistance in this effort.

MJM

 

[jag7720]

About 2 hours... maybe.

Clamp your lines and then remove them.
Pull the glove box out.
"Disco-necked" the heater cables
Un-bolt the heater box from the engine side of the firewall and there is one or two screws on the inside side if the firewall... pull it out, replace the core and re-install the heater box

i am missing a few steps in there but you get the point
It is not too hard. If you can, take the old one out first and take it with you. the local parts house sold me this aluminum POS that was half as thin and didn't work for crap.

 

[Rageous]

Thanks JAG
I know the battery has to be pulled, is the fuel filter in the way?
Thanks again.

 

[jag7720]

I don't remember... I have a spin-on filter in the same location as the OEM and it seems to me that it isn't in the way.

 

[Crash_AF]

You can remove the heater core without removing the engine compartment side of the heater box.

Later,
Joe

 

[jimmy-90]

Ugh...Installing a heater core is a breeze like they say but you definately want to get your original one rebuilt. when I replaced my heater core the parts place gave me some almost useless pos that was about half the thickness of the original one too. I went ahead and put that thing in but you barely get any heat out of it at all. It tries to de-fog the windshield but struggles to even do that on full blast and it definately won't de-ice it. The replacement core is so bad I only wound up bothering with it a couple times all winter long. If you need to drive the truck and don't have time to fix it right away or have to wait on a core rebuild then you can always just run the two heater hoses together with simple brass fittings from the hardware store. I drove my M1028 for a couple weeks like that.

 

[swyne]

I had to get one for my M1028. Buy a quality one don't buy cheap. You only want to do this job once! Right??

Heater Core - Auto Parts Warehouse

 

[edpdx]

You can remove the heater core without removing the engine compartment side of the heater box. 

Later,
Joe

Joe, I have the core from Napa- I figure I'll make the call on rebuiling when I see the old one.

My question is that every other thread I read here says you need to pull a couple of bolts- one of them may require removing the front fender or eve drilling a hole in it to get access to the one pita bolt. When you say that the heater core can be replaced without unbolting anything in the engine compartment to the heater box, do yo mean I can clamp and disconnect the heater hoses to the core and remove only a few screws from the inside and complete the R&R? Have you done this? It sounds like I need to pursue your method... any tips?

Ed

 

[Warthog]

You can remove the heater core without removing the engine compartment side of the heater box. 
 
Later,
Joe

Joe, I have the core from Napa- I figure I'll make the call on rebuiling when I see the old one.

My question is that every other thread I read here says you need to pull a couple of bolts- one of them may require removing the front fender or eve drilling a hole in it to get access to the one pita bolt. When you say that the heater core can be replaced without unbolting anything in the engine compartment to the heater box, do yo mean I can clamp and disconnect the heater hoses to the core and remove only a few screws from the inside and complete the R&R? Have you done this? It sounds like I need to pursue your method... any tips?

Ed

The TM 9-2320-289-20, Section 10-13 covers the heater core replacement.

Only thing in the engine compartment is the drain the radiator, disconnect the heater hoses and remove three mounting nuts. The rest is done from inside the cab.

Remove the glovebox to gain easier access.

 

[Midnight Rider]

You don't have to remove the battery, I didn't. It may be easier to get to the bolts, but it is possible to leave it in there and do the job.

I didn't drain the radiator either. I did spill a some anti-freeze when I was doing this, but I was able to catch most of it.

It was a pain trying to reach all the bolts in the engine bay though. I think I was laying on the air cleaner at one point.

 

[boomer431]

I know on the civy trucks of that era there is a nut below where the blower motor is . You should be able to work an extension and flex socket between the air box and the fenderwell.

 

[junkridge]

You can remove the heater core without removing the engine compartment side of the heater box.

Later,
Joe

Please share how to remove the heater core without removing nuts from engine compartment??????

 

[Welder Sam]

if its anything like a 91 1/2 ton sub..... omg... first time in a decade id paid to have something done

 

[kenz5380]

I know this was already stated, but it deserves to be said twice. I am running one of those replacement aluminum heater cores right now and it SUCKS!! As soon as I have a couple of bucks I'm going to get my original rebuilt and reinstalled.

 

[Miah]

You can remove the heater core without removing the engine compartment side of the heater box.

Later,
Joe

He said engine side heater box, not engine side box bolts...just incase anyone missed that.

I replaced mine a month or so ago & what I ran into was the aftermarket cores had slightly different top tanks & inlet/outlet tube positions so that the upper strap that holds it down wouldn't clear the tubes of the replacement tanks.

Since my core was shot I ended up needing to dremel the grooves in the strap even deeper to get it to fit between the tubes & the body of the replacement core.

 

[jdeoliveira74]

you have to loosen three bolts in the engine compartment. The rest is inside!
not to hard did mine about a month ago. Hard to find a good heatercore I had to use one of those chinese ones made from aluminum. not copper but it worked

 

[NCBloodhound]

I replaced mine on a civy K5. There was nothing to do on the engine side except removing the hoses. Tech manual says the same thing. It really wasn't that bad.

 

[acesneights1]

I know this was already stated, but it deserves to be said twice. I am running one of those replacement aluminum heater cores right now and it SUCKS!! As soon as I have a couple of bucks I'm going to get my original rebuilt and reinstalled.

I did just that. Re core your old one unless you can find NOS. Don't use a Made in China POS. You will regret it. They don't radiate heat. My CUCV had awesome heat until I replaced the HC. I put a Chinese aluminum Knock off POS in. The thing barely blew Luke warm. I had hot water going in and coming out of the hoses. They are half the size of the original. I took it back apart and had my old one re cored and put it back in. Now I could cook a Thanksgiving Turkey on my defroster duct. Here's some pics. The lower bolt for the heater box is a bitch to get to without dropping the wheel well. Since mine was rusted anyway, I yanked it and replaced it. Replace your heater hoses as well.
BTW on a side note that wheelwell came from Keystone, civvy app and the dimples were in it to drill for the rear battery mount so tha was cool.

 

[ssdvc]

Nice pics, thanks !

 

[combatmech]

Awesome info Ace!! Thanks!!