Should I replace the heater core preventatively

So I'm about to do a big service including new hoses, new radiator, new clamps, new water pump, new therm. plus a bunch of other stuff and I was thinking about replacing the heater core at the same time, even though it's not leaking. But I looked around and couldn't find anyone that had one fail. The truck has 225k miles on it.
Is it worth it to replace it? Or is this not a part that fails on Tacos? Anybody have one leak?
Thanks, Todd

 

It's a ton of work to get to that. I would only replace preventively if you were in that far. Better off to spend the time on coolant flush/replacement. I've seen very few failure of the core. The hot water valve seems to go out more often, might be worth replacing it.

 

^^^ This..

Unless you are a glutton for punishment. Here's a video of the process.

https://www.youtube.com/watch?v=mSM3OyeMlWg

 

NO WAY, mine is 22 years old and almost 600,000 miles of water though it and still good.

The heater water valve on the firewall actually will rot from the inside out.
It’s plastic and falls apart in time, that I would replace and the two hoses.

Just be careful removing the hoses from the heater core brass lines, they tend to bend easily.
Best the use a razor and cut the hoses length wise then peel off

 

Unless you have the dash apart and can literally wrap your hands around it, or you want to hate yourself, leave it be. I’ve had several fairly high mileage cars with no heater core issues, and I’d never recommend replacing one that wasn’t leaking.

Unless you want to hate yourself.

 

Very good advice.

 

Have you had any boil over issues that might make it suspect? Talking About when pressure significantly exceeds cap rating not normal coolant transfer to/from reservoir due to expansion. If the radiator has ever plugged it's not unlikely that the core might have as well since they're similar parts of a single system. The cap only limits pressure at the cap where it gets released. Pressure is higher at the heat source, a lot higher if youve exceeded the boil limit of the coolant.

 

If your talking about the heater valve, no.

My. Heater hoses were 22 years old so I decided to replace them when the supercharger was off, easy access.

I tried to get the hoses off the heater valve and the whole plastic valve literally crumbled into a dozen pieces where the hose was connected.

The whole valve was literally just waiting to explode

 

It's supposed to be a low pressure system with the cap being the limiter but things sometimes fail at the weakest point and ignore the safety valve. If you're willing to go to the trouble, remove it, give it a job well done pat, and install a new one and hope the quality is still there. Either way, it seems a bit of a crap shoot these days.

 

The control valve is $103 at McGeorge.

 

DO NOT REPLACE FOR NO REASON! I just replaced the heater core in my 98 Tacoma today and it was a real MFer! I had the engine replaced by some shade tree mechanics back in 2015. While trying to get the hoses loose, they cracked the heater core where the tubing enters the core. I have had it bypassed for several years, but I have recently been reviving the old truck and decided to change it. It took me every bit of 8 hours of diligent work. You will have no reason to be that far into your dash unless your core is leaking or stopped up. Toyota started with the heater core and built the rest of the truck around it!

 

Maybe if you were also doing the EVAP and had every thing pulled apart.

 

Does replacing the Evaporator require a complete dash removal like we see in the picture or can it be done by removing and working behind the glove box?

 

What does Toyota call a "heater core" in the fiche?

When I first brought it home, my truck required a very expensive thing
(87150-04060) replaced behind the dashboard... it didn't involve
coolant leaking or steaming into the cab, but only the air conditioning
worked, and turning dashboard knobs from cold to hot or redirecting
air to different vents including blowing air up onto the windshield (defrost)
didn't work. 87150-04060 is a "radiator assy, heater".

-Mike

 

Wow. That's a universal NO. Thanks for the advice everybody. I'm gonna skip it but I'll check out the control valve.

 

+1 on the control valve. I'm starting a major refresh project also.

 

That's it. They replaced your heater core.

 

I was actually surprised that the complete valve is made of plastic and was total unaware that it was
on the edge of totally crumbling until I did the hose replacement.
But I do have more miles than most on my valve.

 

off-topic (but quasi related) as my mind just flashed back to deep stored memories
was working as a JiffyLube tech in my late teens (early '90s)
a car (don't recall what kind) came in for service during the hot summer
once we opened the hood that plastic reservoir was doing the bust-a-boogaloo all over the place (liquid inside was actually boiling)

that is all i can recall at this time, but soon after that they started making us wear face shields and protective hand/arm wear whenever we opened a radiator cap (while engine was running and no pressure in upper radiator hose)

 

I don’t know for sure, but I would guess you have to pull the entire dash. The heater core is inside the assembly box pictured in my original reply. That box is behind the radio. The evaporator is behind the glove box, but it is connected in line with the heater core box and all of the ventilation. It might be possible to get to it without removing the entire dash, but it’s still going to be a job!