tgreco

On my way home yesterday, my heater core decided to give up the ghost. Apparently, my passenger side floor board was jealous of the radiator.

I found a good tech write-up (see below) and have ordered a new heater core, but I still have a couple of questions as I want to make sure and not be delayed due to special order items. The truck is a 1981 Pickup 22r SR5.

http://www.toyotanation.com/forum/80...placement.html

1. What typically fails on the heater core? Is it typically a seal or can the metal coolant lines crack/bust?
2. Are there any other parts of the heater mechanism that should be serviced / replaced while I have the entire dash off the truck?

For others looking to replace their heater core, don't expect to run out to your local auto parts store to find a replacement. All physical stores had to at least order the part, and for most it was a special order item (Napa, Pep Boys, etc). O'Reilly's was the cheapest I found and was similar to online sites (Rock Auto, etc). Toyota has actually discontinued the heater core for this model so don't expect to get it from them.

83

There are always a million things you could do while you're there...but there's really very little you need to take apart to get to your core.

Ignore 95% of the steps in that link you posted.

All I remember doing to replace my core was taking a couple screws out of the glove box and pulling some heater ducting. It's seriously a 1 hour job in these trucks.

So...you could make sure all your cables and hinges for the heat/heater hoses are lubed and moving smoothly, and check out all the wiring while you're under there.

But really, just get the glove box and heater tube out of the way, take the old one out, new one in, DONE.

It was about 1 1/2 years ago that I did mine, so I'm probably slightly oversimplifying it, but it really is no big deal to replace the core in these trucks. Once you get into second gen and later models, things get a lot more complicated...

Mostly what happens in they get clogged and/or crack, and the inlet or outlet tube cracks.

tgreco

Thanks for the reply. I started on the tear down yesterday, and it seems like I have to take a few more things off besides the glove box to access all of the mounting hardware. This is of less concern than the actual fix.

If in fact one of the metal coolant pipes is cracked, what would be the best way to repair these. I imagine that a replacement may be impossible to find. A couple of thoughts on the subject:

1. cut out cracked portion and replace with rubber coolant hose
2. JB weld or something similar to patch the crack (probably not ideal)

My concern may be if the pipe is cracked near the inlet or outlet to the heater core. Would it be possible to fab a new rigid coolant line out of copper pipe (or another bendable material) with the same diameter as of the OEM pipe.

83

I would just buy a new heater core. They aren't that expensive, and they are exactly like your radiator. Rather than patching and fixing and rigging an old failing radiator, why not just replace it?

They don't make replacement parts for heater cores, just replacement heater cores. Aren't they all one peice? The heater core just has metal lines coming out of it, and they go through the firewall and connect to rubber hoses.

Do you have AC? I don't. I wonder if that's the difference. I absolutely did NOT need to take my dash or instrument cluster out/apart.

RobotMoose

iTrader: (1)

Even the A/C version is still pretty simple, but the heater box is about twice the size as the non-A/C. All the screws should be accessible through the glove box, or behind the SR5 Oil and Volt gauge pod (if you have one). I think removing the radio bay facade will make things easier to reach, though.

We are all blessed by the simplicity of these trucks.

tgreco

I do have a/c (although I have removed the pump from the block) and the SR5 gage cluster (oil pres and batt), and that is likely why I am having to pull more off the dash to get at the heater box mounting hardware.

I did purchase a new heater core, but I am concerned about what actually failed and caused the leak. Hopefully it is only the heater core, but I am concerned about any other potential failures (i.e. the metal pipes).

I will be pulling it off this weekend and hopefully will report back on the fix and not with more questions.

RobotMoose

iTrader: (1)

with the exception of a few junction pieces, there really aren't any metal pipes in the heater loop of these trucks, it's all rubber hose.
Heater core failure is a common problem in older cars and trucks, they're built like radiators, and over time, the soldered joints break down.

It's just as likely a heater hose has failed as a heater core, and would be worth your while to get everything squared away at once. An easy test is to disconnect your heater hoses from your coolant loop and water pump. block up one end, and rig up a garden hose to the other, pressurize the line and look for leaks.
You've mentioned that your passenger's side floor became Lake Passenger's Side Floor, so to me, that indicates a heater core failure.

83

Again, like I said, it's all one piece, right? The metal hoses are PART OF the heater core. So the new one you bought will have new ones attached to it. Then they go through the firewall, and the rubber hose connects to them.

tgreco

Got it replaced yesterday. So, there are 2 metal pipes that connect to the rubber lines at the firewall. These do not connect directly to the heater core but are connected to the heater core via short rubber heater hose ~ 2 inches long.

The failure occurred within the heater core - cracked coolant passage.

To get the heater/fan assembly out, I had to remove the glove box, oil/batt gage, a/c apparatus under the glove box, radio face plate, and various duct work. Took about 3 hrs to do start to finish.

83

Glad you got it done!

tgreco

Thanks for the input from everyone.

As has been typical with this truck, it was surprisingly simple.

Dknight420

I’m in the process of replacing mine now. How did the foam on your box and core look? I want to replace it because the leak destroyed it. Any suggestions? Cheers!

Lons81

iTrader: (2)

You can buy different thickness foam with sticky backing and reline the parts. Check your local hardware store