OE heater core and T's busted (1 Viewer)

[bluesquirrel]

Just bought my 98 LC a little over a month ago, and have 223,900ish miles on it. A few weeks ago, I was driving in the cold and tried turning on the heater... No go. Messing with it later on I found that the servo motor was not moving the mixer doors for the heater.

Reading through the forums, I've come to learn a lot about the truck's cooling system, and upon seeing red crystalizing around the heater hoses, I decided to replace everything...

So, the hot side T disintegrated in my fingers. The servo below the heater core was covered in red and rusted, and the core was toast.

223+ thousand miles on OE fittings and heater core? Wow.
Pics to follow, in case anyone finds them useful.

 

[bluesquirrel]

We all know these

Had to pull the whole box out, to get to the servo underneath.

 

[bluesquirrel]

How bad the servo linkages looked.

And the core

 

[gil12]

Thanks for the pictures. That is quite a job. How much trouble was it to get that out of the dash?

 

[Sandroad]

Interesting. The corrosion seems odd. What's the history of the truck? Windshield leak? Flood? Blocked drain? Rodent damage? Any other corrosion under the dash? Looks like a big job.

 

[bluesquirrel]

Thanks for the pictures. That is quite a job. How much trouble was it to get that out of the dash?

I've taken apart a couple Toyota dashboards in the past, so they don't scare me. But this thing has more wires than the space shuttle.

@Sandroad , There was no other corrosion, and the red color is the nasty engine coolant that came out. unfortunately I bought from a dealer and have limited history on it. That's the main reason I'm going to all this trouble. I want to have a baseline of maintenance.

 

[2001LC]

Wow big job. Is it rust or crud from core leaking some nasty stuff?

 

[Sandroad]

Wow, that photo of the disassembled dash is epic!

 

[bluesquirrel]

Wow big job. Is it rust or crud from core leaking some nasty stuff?

Pretty sure it's the nasty engine coolant leaking, but the metal servo parts sustained corrosion from that leak. It sits directly beneath the heater core

 

[2001LC]

Hope Dealer doesn't nick your wallet to badly.

This illustrates the importance of a proper flushing routine. I'm adding more in-depth coolant system during inspection, with pressure test. I'm also adding this area to it now, after seeing this job.

 

[bluesquirrel]

For the wallet, I'm willing to invest in this work and replacements. I'm certain, after looking at the parts, EVERYTHING is original components, and the engine coolant system was never flushed. I'll be glad when I'm done

 

[bluesquirrel]

@2001LC if you're curious, a 98 LC heater core is north of $400 from Toyota.

My butt hurts now

 

[bluesquirrel]

Because I know there are curious lurkers like me here, I took pics of the servo damage. The leaking coolant infiltrated the servo gear and gummed up the rotating electrical contacts. If you look closely, you'll see a total of 11 contact brushes. These correspond with the 11 settings displayed on the dash temp knob. This servo is around $150 - $200.

 

[bluesquirrel]

 

[nissanh]

Many other toyota blend doors have wornout plastic wheel (the big one with the contact points). Noticing it is a 98 and 224K miles, I find quite confident of the material used in the parts used in a cruiser including the blend door. The 2000 has the same blend door with same number of wires.

 

[bluesquirrel]

Many other toyota blend doors have wornout plastic wheel (the big one with the contact points). Noticing it is a 98 and 224K miles, I find quite confident of the material used in the parts used in a cruiser including the blend door. The 2000 has the same blend door with same number of wires.

I thought about that, but after some electrical checking, and opening the servo, I found the connections to be beyond repair. I was happy to see the plastic gears were in great shape though.

 

[bluesquirrel]

If anyone was curious, the part number for the servo assembly under the heater core is 87106-60120. The parts diagrams do not show it's location, only that it's part of the heater box assembly. Part number 87106-60110 is the servo on the driver side of the heater box

 

[Muddy Bean]

You have my respect squirrel.

I will now beg the heater core gods to leave me be. I want no part of this.

 

[bluesquirrel]

You really don't...

 

[bluesquirrel]

While replacing parts associated with this repair, I broke a flap door inside the heater box....
The entire heater box assy is ~ $800 from Toyota, and comes from Japan. So I'll have it in about two weeks, and I can finally get the truck running again.