Heater core replacement

[WSG1970]

I searched but haven't seen anything here. Is there a write up on heater core replacement on vanwagons?

I have seen where the hoses disappear behind the dash but it looks pretty involved. 😁😁

[brentlehr]

From my Chilton Manual:

"The heater core is incorporated into the cooling assembly housing and therefore cannot be removed with out removing the cooling unit assembly and splitting the case into two halves. Refer to evaporator removal and installation for heater core removal procedures on vehicles equipped with air conditioning."

So basically after removing the the connections to cooling unit and capping you remove the glove box with under cover, unplug all connectors (A/C harness and pressure switch) then unbolt the cooling unit. Then you have to open it up or replace with a good unit. Download the factory service manual and check for a diagram. https://drive.google.com/file/d/1q4u_5zlshRsVDv5v86CiukP7wOD7nKyF/view

We need to make a sticky for that link somewhere.

[coronan]

I am looking for the same information.

The heater core does not appear in the 87 Van Manual.
Neither in the Cooling or Airconditioning sections.

[brentlehr]

Chilton's manual refers you to the section on removal and disassembly of the cooling unit b/c they are integral, not separate assemblies (But there's no diagram, just the text I posted above). That procedure starts on page AC-39 of the 87 van manual and includes a diagram. There may be extra parts not in the diagram. Strange they don't mention heater core specifically.

But the starting step is to remove the glove box and under cover. Then it should all be visible and at least you can get a better look.

I know there have been other threads around people not getting heat and cleaning the heater core is something they've done. Maybe they'll chime in.

This is helpful for following your heater lines. http://www.toyotavantech.com/forum/showthread.php?67-Getting-to-know-all-the-coolant-hoses-of-your-Vanwagon

[WSG1970]

I am looking for the same information.

The heater core does not appear in the 87 Van Manual.
Neither in the Cooling or Airconditioning sections.

I can see where the heater hoses go in underneath the fronted the van, and the heater core looks to be well anchored behind most of the dash. I have read enough to understand that the AC system will be discharged by going after the core. My AC isn't currently working so that's really a non issue. The fogging front windshield during defrost and the slight sweet smell of antifreeze kinda makes me think it's just a tiny leak there though.

I have been contemplating some brand of stop-leak for the coolant system but am wary because of the cooling issues with these vans to begin with. I have just replaced my head gasket and am enjoying a happy temp gauge currently and hate to jinx it.

[djshimon]

What's the reason for you wanting to replace heater core? If you don't have heat, just flush the core forward and backwards-it's really pretty easy. Have some extra coolant to replace what you lost. And replace your old hoses with bulk hose for real cheap.
I haven't removed the core(and hope i never have to)but I can't imagine it being easier than a flush.

[JDM VANMAN]

I removed a heater core earlier this year and let's just say it's a good thing I didn't have to put everything back together again. I was after the fuse box that was in immaculate condition out if a 87' cargo conversion van that only had 187k miles, once I was in there and I decided to go all the way and take everything apart-

I removed the-

1) dash pad
2) stereo bezel
3) fuse box
4) heater controls
5) all the vent tubing
6) some big black box thingy?? And behind that buried deeeeeep was the heater core.


I took pictures but my hands were a mess and the pics didn't come out that clear.

Check it out-

[WSG1970]

What's the reason for you wanting to replace heater core? If you don't have heat, just flush the core forward and backwards-it's really pretty easy. Have some extra coolant to replace what you lost. And replace your old hoses with bulk hose for real cheap.
I haven't removed the core(and hope i never have to)but I can't imagine it being easier than a flush.

The smell of antifreeze when the heater is running, and the foggy front windshield when the defroster is on. Those are the main reasons.

[coronan]

Hey finally some pictures! Thanks jdm!
I swapped mine last weekend. But with out removing the dash pad. I'll post photos this weekend.

Unlike the rumors in the manuals, the heater core is not integrated into the a.c. Evaporator.

[coronan]

So i was able to remove my heater core and leave the dash pad in.
The heater core is not integrated into the AC evaperator housing. It is behind the Radio.

In order to get the AC cooling unit out, I removed 2 bolts holding the metal bar. Those 2 bolts are above the passenger side speaker.
3202

The AC unit is only held by 2 about 2 bolts, 1 on the bottom, on on the top front.
Roll the top of the unit down toward you to get it out.
3210

3211

remove the center console, and radio. There is a black triangle shape piece of metal held by to screws on the passenger side i removed as well. This gave a lot of wiggle room and visibility for the following steps.
3203

I forgot to get pictures of removing the fuse box. There are about 8 plugs, I'm pretty sure they are all proprietary.

2 cables are attached to the heater unit.
1 on the drivers side for the vent select.
3204


1 on the passenger side, on the bottom for the temp control.
3205

Here are the heater core hose connections. I like to pry them down with a pry bar from in front of the bumper.
3206

The Dash harness need to be separated from the chassis harness, behind the radio.
3207

[coronan]

The floor vent is only snapped in place with 2 tabs in the front and 1 in the back.
3214

The white duct is secured by 1 screw. wiggle it down the pull to the passenger side to remove.
3215

Here is what is left. The heater core housing is only held by 1 nut on the bottom right. and 1 screw on the left above the gas pedal.
3216

I rolled it down and out like the AC evaporator housing.
3217

Here is the heater core housing removed. To split the case there are a few screws and several metal clips. Make sure the metal clips don't go flying across the room.
3218

[coronan]

I ordered a STANT 90609 from rock auto. It fits but its not as thick. And does not come with foam.
3219

It looks like APDI/PRO 9010177 would be a better choice as according to the dimensions listed.
https://www.rockauto.com/catalog/moreinfo.php?pk=3607236&cc=1279784&jnid=448&jpid=0

I happened to have 3/8 thick weather stripping that worked perfect.

Here is the cancer in my old heater core. I have back flushed and vinegar washed my cooling system about 3 times since i have owned my van (7 ish years). And I always use distilled water when filling the system.

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The hot cold lever controls 2 cables. 1 is the valve in the coolant line under the van. The other is a damper that can by pass the air flowing over the heater core. If your not getting any heat this alone could be why.
Here is the damper door in the HOT position.
3222

Here is the damper door in the COLD position.
3223

H= Hot / C = Cold for the control lever. This stuff is never in the manual.
3224

On the other end of the box is the vent select controls.
F = Floor
V = Upper vents
D = Defrost

There is a lever in the white ducting as well that connects to the vent select linkage. I cant remember what is does.
3225

Install in reverse order.

I used a little bit of silicone to close the cap where the heater core tubes pass through the sheet metal.

I hope this takes some of the mystery out of the exploratory surgery.

[brentlehr]

This is awesome! Thanks for the pics and detail. :thmbup:

[timsrv]

Yes! Thank you very much for your detailed post :thmbup:. I have had close to 20 vans (so far) and have yet to have an issue with a heater core (knock on wood). I'm really glad you beat me to it as your post will no doubt save me a bunch of time. The other thing is knowing for sure the job is possible......lol. This is one job I have been dreading (fear of the unknown). It's not so scary now........thanks to you. Tim

[siskiyoudaniel]

Great write up and pictures... thank you. I have one question about replacing a heater core; while it's out should one flush out any other parts of the system to avoid plugging up the new core?

I just got a van that has no heat (and it's still really cold in the am here)... it was running on the cool end (about 20% up the gauge at idle after warmed up) so I thought maybe it was the thermostat stuck open... replaced the 'stat - no change in hot air temp (the van is now running a little warmer, closer to 35-40%, the old 'stat gasket was shot). I pulled the hoses and back-flushed the core and there was some really really dirty, rusty sludge that came out and the flow-rate was terrible. The water cleared up eventually but the flow-rate remained minimal. Pulsing helped dislodge more dirt but after 1/2 hour the flow-rate was still meager in reverse flow and non-existent in forward flow. So I ordered a new core which should be here this week. My question is, can I just install it and roll or should I flush the entire system (or part of the system) to protect the new core :cnfsd:. The coolant looks good in the reservoir and the stuff that came out when I changed the thermostat looked good. The PO changed the coolant two or three months ago.

Thanks for any advice.

[coronan]

I would drain the coolant and pull the thermostat. Put in 1 gal distilled white vinegar + distilled water. And drive it that way for a day or 2. (so long as you don't have a freeze risk)

That will loosen up scale in the engine and radiator.
Then flush it forward and backwards.

Don't forget to use the block drain behind the alternator.

[siskiyoudaniel]

I would drain the coolant and pull the thermostat. Put in 1 gal distilled white vinegar + distilled water. And drive it that way for a day or 2. (so long as you don't have a freeze risk)

That will loosen up scale in the engine and radiator.
Then flush it forward and backwards.

Don't forget to use the block drain behind the alternator.

Oh man. That thermostat was a tedious job... I was not looking to go through that again any time soon.

Thanks for the advice.

[coronan]

If the thermostat is closed the chunks wont come out while flushing with cold water.
Unless you flush with HOT water directly from the water heater. Be careful.

A lot of work on the van is only a B*tch the first time. Some things that help are wobble extensions.
http://www.harborfreight.com/9-pc-wobble-socket-extension-set-67971.html

And maybe a 1" extension.
Keep a magnet near by, cause if you drop a nut they disappear into a ledge just above the oil pan and motor mount.

[Rufus]

Well I am glad to see Rufus has a new owner who will treat him good. If I were closer I would come help with the job.

[siskiyoudaniel]

So I ended up taking everything out.

3439 Here it is in progress.

My hands were not nimble enough to be as surgical as coronan.

I ended up pulling all of the duct work while I was in there. It all seems straightforward enough to reassemble (after it all gets cleaned up) and the new heater core fits nicely.

3440


I do have one hurdle to clear before reassembly... the linkage on the left (driver's) side of the heater core housing (see last photo in coronon's write-up) has one spring that seems to somehow connect to what he refers to as the "vent select linkage". This spring is broken and I'm not sure where one end of it attaches. The exploded diagram I viewed was not detailed enough to show the linkage assembly or spring.


3441

3442


Any body have an idea where this spring goes or how to get a replacement?

Cheers,
Daniel

[coronan]

I don't believe the "spring" is broken. I should mate with the white damper arm.
I Marked it in red.

3443

[siskiyoudaniel]

So just pop it in there?!?

That would be the greatest fix ever!

Thanks, I'll check it out when I get home.

[Busyboy]

This is awesome! Thanks for the pics and detail. :thumbsup:
Yes, very good of you to post this and save me exploratory surgery. So helpful