'94 heater core R/R - done (2 Viewers)

[sandcruiser]

it *is* a lot of work
taking photos as you pull stuff apart is a good tool to have for re-assembly
also, putting fasteners into ziploc bags with notes as to what they fasten can only help

I painted some of the metal parts while there, long term maintenance. I also bundled up wiring that had been fiddling with over the decades, and put parts of the harness into split-loom to reduce friction/rattles

I also added a kill switch and a switch for my aux lighting while I was there. It's much easier to do when you've got the dash out of the way.

the big "gotcha" for me was remembering where the various parts of the wiring harness need to go. They interfere with putting the pieces back together if you route them wrong.

 

[ripple]

I just got my heater core but it didn't come with lines attached....
It's a 97 and I heard there was something different. It's all aluminum. Will I need to
"unsolder" the orignal pipes off of the old core? I haven't removed the
dash yet, waiting on a warm front.

 

[Higgin]

Guyute.....if you are having trouble locating the anntenna wire and have already mounted a cb antenna, check out the Firestick AR-1. It basically allows you to use your cb antenna for your cb, but also for your am/fm radio antenna. My factory ant. was broke when I bought the truck an reception was limited to to <20 miles from the brodcast area. I came across the AR-1 when I was installing my cb and ended up installing a 5foot whip ant. on my front bumper and using the ar-1 instead of replacing the facotry antenna. And wow! That thing works! I had my doubts, but figured what the heck and tried it for $20. Now i can pickup stations much farther away than with any other vehicle I've had. And it didn't effect the cb preformance at all as far as I can tell. I get good range on that also. The only problem I had with the unot, is that it was hard to find a spot in the dash to put it. The wires comming off it are only maybe 12 inches long, so you are limited where you can put the actual unit. I ended up moving my rear heater switch over to the left one slot, and that gave me just enough room to put it behiond the dash where the heater switch used to be. BTW....I have the same CB radio as you, and installe dthe same way!

 

[l1coeea9]

fwiw: I couldn't get the heater core out w/o removing the AC housing. I was too worried I'd bust the AC lines

just a data point

I'm about to start to replace my heater core.

Does the A/C cooling unit have to be disassembled? That would require discharging the refrigerant?

Sounds like the A/C should be delt with first before working on the heater core?

 

[75BRONCO]

Getting ready to change out the heater core on a 94. One thing I noticed on the new core is that the tubes have two different fittings. One seems to have a rubber hose slid over it and clamped. The other I am not sure, it kind of looks like a compression fitting. Is that right?

 

[aim]

On my '94, the heater core had a "flared fitting" sort of deal (on the driver side of the heater core) that was sealed with an o-ring and held together with a copper clip. Basically, you slide the core and the short pipe together, and the o-ring gets trapped between the two matching flares that face each other. The copper clip is s spring clip that then squeezes the lips of the two flared portions together.

If you buy the "complete" heater core, you get those parts. If you buy the "bare" heater core, you don't. I agonized over that o-ring for days; ended up replacing it with another o-ring that was a very close fit. That, a mere soupçon of silicon grease and a reused copper clip. Of course, that joint is in the passenger compartment, way inside the dash.

Don't stress the clip, be careful with the o-ring and be *really* careful with the short copper pipe that comes from the heater core and goes through the firewall.

By the way, I managed to pull out my heater core without cracking the A/C. When *all* the fasteners were removed, there was just enough play to slide it out.Pointless, as it turns out, since my A/C was empty.

 

[75BRONCO]

It probably makes sense to get the new o ring and clip, because it is so far in the dash.

Has anyone else been able to remove the core without removing the ac

 

[aim]

I couldn't get the o-ring and clip without buying the "complete " heater core at double the price.

 

[75BRONCO]

Well got it! Took 12 hrs. I did not crack the ac. Was able to do it without discharging. Was a lot of stuff, as recommend in a previous post, take lots of pics. Especially of the wiring harness ams where it routes around the support and dash.

 

[Sc0-]

What happened to the pics? I am currently trying to figure out where a wire goes that comes from a sensor underneathe the heater core...

 

[Guyute]

What happened to the pics? I am currently trying to figure out where a wire goes that comes from a sensor underneathe the heater core...

Not sure on the pictures...I do still have copies on my home PC.

Did this years ago... and honestly. I try to forget about it. Scary mess.

Let me know what you are looking for and I'll see if I have any pictures that show it.

 

[tfree]

Sweet Syrup Smell

Any chance I can get the pics that go with your heater core replacement post?

 

[tone33]

Any chance I can get the pics that go with your heater core replacement post?

X2 on pic request. Still diagnosing but looks like I might be taking on this job on my 150k 95.

 

[sandcruiser]

The pics arent likely to help diagnose.
Take many of your own as you tear into it. Video even.
Its a lot of parts.

Also, before you start, consider listing anything else you want to do behind the dash. Switches, antenna, stereo upgrade, kill, etc. When the whole dash is out, youve got some room to do that stuff.

 

[tone33]

yea i'll try to get some pics and post them. I was hoping that it wasn't my heater core, but looks like it is. coolant dripping on pass. floorboard, windows fogging up really bad, coolant smell in cab when heat is on.

I'm definitely going to dynamat around the tranny hump, and maybe a few other places. not sure about switches/electronics - need to come up with a long term plan of everything i want to add first...

The pics arent likely to help diagnose.
Take many of your own as you tear into it. Video even.
Its a lot of parts.

Also, before you start, consider listing anything else you want to do behind the dash. Switches, antenna, stereo upgrade, kill, etc. When the whole dash is out, youve got some room to do that stuff.

 

[tone33]

Here are pics from my recent heater core replace - they should be in order of tear down. No write up to go along with it at this point, but hopefully the pics will help someone else!

https://flic.kr/s/aHsjWDLmQ6

 

[Guyute]

Well it's back together and on the road again. Took me two weekends and a few hours here and there. I'm slow and distracted easily so that doesn't help.

This 80 has a little over 200K miles. Had the classic interior fogging and slight anti-freeze smell. We had a A/C leak before this so I had taken it halfway apart before.

Took a ton of pictures to help put things back together correctly. The pictures helped mostly on the routing of wire looms and such. The plugs only seem to fit the correct switch.

The FSM does a good job of leading you through most of it. Dropping the steering column helps a ton.

I'll post some pictures now...

Careful not to break these little tabs on this main upper trim piece>

 

[Guyute]

locker, dimmer, mirror and OEM security>

Speedo and stuff>

 

[Guyute]

I've had a 'D' bulb on the shelf for about 5 years. Forgot to put it in while it was all apart! Doh!

Hidden bolt under the false vent (US passenger side)>

n00dly appendages>

Gooey center>

Cross support bar was kind of a PITA to get out>

New core and CB. Also replaced heater hoses while I was there.

 

[Guyute]

There is your problem>