More Pink Milkshake

But what does that mean if you have both?

 

You should keep it OEM and not over worry on this. Coolant should be changed (flush and fill) every 4 years. Older vehicles sooner as corrosion works faster the older they become.

Re-enginnering may cause you other problems and I assume added expense in the redo? Worst thing that can happen is your tranny blows $2-3k? Thats 3 new monthly truck payments.

At some point our trannys will go just due to age. When they do, the beauty is they can be rebuilt better than new.

Conclusion: Stop over thinking and change that radiator and thermostat. Flush it. Fill it with ethylene glycol type. Drive it with a smile.

 

My 3rd gen 4runner had the original radiator at 186k. The bottom fittings looked bad.

I drained everything, swapped it with a Napa unit. When I did this I capped off the tranny cooler fittings on the new radiator. I installed a B&M aux cooler behind my grille and ran new lines. It was this way for another 90k until I sold it. I offroaded frequently, pulled a 4000lb boat a few times a month, and never had one issue.

I wanted the piece of mind knowing that a pink milkshake could never occour.

 

I don't know that crack is the best description to use regarding this type of failure. The pictures above clearly show the two types of in-tank transmission fluid heat exchangers "coolers" that are used. Stacked plate and concentric tube. My internet searches in Toyota, GM, and Honda forums seems to place the failure at the threads and o-rings for a stacked plate, or the brazed joint between the nipple/barb and main body on the concentric. Poster Sharmstr, who is in the radiator manufacturing business, also commented that Chinese manufacturers are using steel concentric tubes that may be susceptible to corrosion at the end plates and barbs that can cause a fluid exchange once the anti-rust properties of the coolant wear off over time. I also remember a post saying that the Chinese concentric coolers no longer have brazed end caps, but epoxy'd endcaps that also fail and leak after years of thermal expansion and cooling cycles. I'll go back to my Denso email and ask if they can give more detail about the cooler they use.

 

Do a couple of searches, there's more than a few posts that discuss the reason for the in radiator heat exchanger. Most say the engineers designed the transmission to operate best with fluid between 150-180f. And yes the OEM setup is in series. Hot tranny fluid to radiator heat exchanger, (intercooler terminology really isn't appropriate here), heat exchanger immersed in coolant transfers heat 20x faster that air, fluid than goes to auxiliary air cooler, then back to trans pan. The aux fluid to air cooler is usually installed with a towing package to help ensure the fluid gets cooled enough in the event of severe use like pulling a 6k trailer over a 9,000' mountain out west. IIN those conditions the fluid may enter the radiator as hot as 280-300f and may not have enough time in the heat exchanger to cool down to 180, so sending it to a final aux cooler helps bring the temps down a little further.

 

It seems they would want it to be the opposite, as in a cold climate the fluid is coming out of the radiator at 180 and then going through a cooler, which depending an ambient temps, could drop the temp well below 180.

Going the other way, it blows of excess heat first and then gets raised or lowered to 180 in the radiator regardless of ambient temps.

In any case, I didn't realize the external cooler wasn't standard. Mine came with it. What else goes into a tow package?

 

Looks like Denso may be the best replacement choice based on this email from them. If accurate, it seems they've done as much as possible to prevent coolant to atf mixing. Here's their reply:

• Its Aluminum
• Brazed

No other information available
DENSO Products & Service Americas, Inc.
Technical Services Department

Can you please provide any details regarding the atf cooler for this model.

Is it concentric or stacked plate?

Aluminum, brass, or steel?

Are cooler joints welded, brazed, epoxyed?

Rate of return or failure of the atf cooler?

Thanks.

 

Well, I got my Denso radiator. I will say, it was extremely poorly packed and both transmission coolant connectors were sticking out through the box and bent, and one side was bashed, resulting in a visible bend in the tubes near the edge when compared to the straight edge of the bracket.

The brackets where also crap and missing some of the hardware, I reused the original brackets.

If it wasn't about 5º and I really need this truck running I would have sent it back. This kind of bad packing is completely unacceptable. I have ordered other radiators in the past and never had anything like this happen.

 

Sorry to hear that. Others on Amazon had the same complaint.

 

My Denso from Amazon arrived in 100% perfect condition, $95 - beat that. Just use Prime and if its bad, free return/exchange. Luck and enjoy those Toyotas. : ^ )))

 

Your last two photos of the cooler show the weak point that causes the pink milkshake. I have one from a 4Runner that I similarly disected following a pink milkshake failure. I'm about to head out of the house, but when I get back, I'll post photos of why and how it failed. Spoiler alert: it's the fittings where the tranmission cooler comes in/out of the radiator tank.

This is well documented problem with Tacomas and 4Runners, but also with some Honda products - particularly the Ridgeline (which uses a Denso radiator). The "updated" Ridgeline radiators use a different fitting.

 

Yup 4runners prone to it too. Lots of great info at Tr4.org Here are some examples to see pinkmilk shake pics that horrify: More info at TR4.org: Bottom line - if you have any concern on whatever vehicle you have that uses an internal trans cooler within the radiator (at bottom) then swap for a new high quality radiator about every 8-10 years. By-pass it if you want, may heat up more if summer towing on hills and/or stop/go situations - monitor those temps. Luck and enjoy the Toyotas. : ^ )))

 

Just for informational purposes... when you change your coolant, DO NOT USE tap water... buy a gallon or 2 or distilled water (or boil your own). This will reduce the contaminants that speed up the corrosion process. And when done, pre-mix a gallon to have for "top off" needs

 

Good advice....just make sure you didn't buy a jug of prediluted anti-freeze first...sometimes it's not that obvious on the jug.

 

Why complicate things? Just buy the pre-mix stuff. Costs a small amount more, but so much easier. Asian Pink Zerex is perfectly priced and has all the Japanese certifications.

 

As promised:

This ATF cooler was in the radiator of a 2002 4Runner that suffered a pink milkshake. You can see the poor design of the fittings makes is susceptible to corrosion and oxidation from both the inside and the outside. When that happens, it allows the two fluids to mix because the connection is made insided the radiator. It's all aluminum too -- which someone pointed out earlier, is great for reducing cost, but not so great for longevity.

 

In contrast, here's the cooler that came out of my Volvo 940T (from 15 years ago). The plastic tank developed a crack so I replaced the radiator. But as you can see, the cooler is still in perfectly fine condition. But the design of this cooler is such that if the seal between the radiator and the cooler failed, it would simply start dripping coolant. If the connections to the ATF lines were to fail, it would start dripping ATF. But the only way the two fluids can mix is if the cooler itself fails. Which is much more robustly designed than the Toyota part, and it's made of copper, not aluminum.
And, @Professional Hand Model... no wise cracks about my amateur caliber hand modeling work!

 

Common plastic to metal radiator failure on all mfgr's vehicles eventually happen, even though it takes awhile. Go for an all aluminum radiator when OEM fails. A good example above others is https://www.championradiators.com/Toyota-Tundra-Radiator-2000-2006

 

Can anyone clarify the frequency of the pink milkshake/radiator failure in Tundras? Common? Or as common as the 3rd Gen 4Runner?

I recently lost a 2002 4Runner to a failed radiator. I was aware the 4Runners were prone to this (yes, I knew of it and didn't proactively swap the rad, it was on my "To Do" list) but I have not heard that Tundras are susceptible to this as well. Although it makes sense after reading this thread as it's probably essentially the same radiator.

Point being if it is a common known issue my next purchase will be a Denso radiator. I can't afford to lose another vehicle to the dreaded milkshake.

 

I would say the potential is there since the cooler and fittings appear to be the same design. But I don't recall having read of anyone on this forum who's had the problem. So based on anecdotal evidence, I'd say it's not as common as with 3rd Gen 4Runners.

And on an unrelated note: is your avitar Cam Neely in Super Troopers? (If so... cool!)

 

Same here. I don't beleive it's that common but replacing an aging radiator is probably cheap insurance.

That's Sea Bass from Dumb N Bumber.

 

Per this quote (see #452 on this posting), Not possible because the design on all gens was not the same as the 4Runners (yours RIP), no fluid to fluid cooling.

https://www.tundras.com/threads/2019-5-7-trans-cooler-location.33216/page-16

Luck and enjoy those Toyotas. : ^ ))))

 

Had to look that up... I didn't remember the character from the movie. Turns out I was half right: it is Cam Neely. Pretty funny.

 

Quoted from that post:
Prior parts research indicates @timsp8 is correct. Since 2000, Tundras have never used ATF heat exchangers in the radiator tanks. The earliest models used stand-alone air/ATF coolers without temperature regulation. I believe some early (Gen1?) Tundras had a power steering fluid cooler in the lower radiator tank...that may have been the early source for "pink milkshake" (if red ATF was used in the PS).

So the cooler circuit in the above pics by @Aerindel is for the ATF?

 

Yes, its for the ATF. My tundra also as a secondary cooler as well.

I'm confused...because mine absolutely does have an ATF heat exchanger in the tank.

Are you trying to say thats not tranny fluid but power steering fluid instead?

 

Yes, avatar is Seabass from Dumb & Dumber. I've been using Seabass as my forum avatar for about ten years. He was a beast of a hockey player.

So the rad design is different on the Tundras compared the the 4Runners, no possibility of inter-mix? That would be reassuring to know. I basically lost a very good 4Runner to inter-mix. It was a killer gut punch.

 

Yep. I know when I replaced my radiator earlier this year I had to disconnect 1 or 2(can't remember) lines that had ATF flowing into the bottom of the radiator.

 

Yep, two lines.

 

I don't think that's correct. We're saying it's possible, but doesn't seem to happen very often. If you do a google search you can find old posts about it.

 

Anybody ever use one of these? If came up on big gurl under products that fit my 06 double cab.

Liland 2321AA RADIATOR

https://www.amazon.com/LILAND-Liland-2321AA-RADIATOR/dp/B01M04AD3G/

All aluminum and looks similar at first appearance to the champion. The champion was showing out of stock.