Technical reason for the pink milkshake?

[Jhelms]

I keep reading and reading.. Cannot find a single fact on why it occurs other than a radiator failure. Is it because of corrosion from not changing radiator fluid / going acidic? Or is it because of a physical failure like tank separation? Anyone have photos of WHY?

I have read stories of people saying "oh it happened to me at only 100K miles and the truck always had toyota red coolant in it" However they fail to mention that the truck has had the SAME toyota red coolant since 1998 for example lol

Just trying to dive into the WHY it happens. Piss poor maintenance or none at all to the coolant system? An actual physical failure? What are the FACTS?

If it is corrosion, this all sounds to me more like the people with failed heater cores. They generally do not fail for no reason at all, it is because coolant has been left in them for ages (they never use the heater) or the coolant itself has gone acidic / causing electrolysis and has rotted the core out. In lots of warmer climates, we never turn our heaters on for example so even if we flush or drain/fill our coolant system, the heater core holds OLD coolant.

Has anyone checked the PH of their coolant or what is left of it after a pink milkshake or done a voltage test on the coolant? Not sure what can be done with tranny fluid mixed in or if the measurements would even be valid.



Edit: I did find these photos of a NON milkshake radiator teardown. Would love to see some with the actual failure and where the failure actually occurred.
http://forum.ih8mud.com/threads/my-radiator.509682/

 

[cashmoney]

My family and I have always neglected coolant systems to the point of never changing it even at 200k miles. Never once had a failure of any kind of any component in the cooling system. This is of various makes of vehicles (chevy, dodge, infiniti, ford).

Now, with that said, I can't say that lack of maintenance isn't the main cause of the milkshake. Maybe Toyota's radiators are a different alloy, maybe the Toyota coolant breaks down and becomes more acidic than others. Dunno. But I'm willing to bet that it's a combination of physical failure (poor build or material) and lack of maintenance combined causing it.

Another data point, stock radiator was in my runner at 217k when I bought it. Heater core had failed but no pink milkshake. Coolant had never been changed prior to the water pump and timing belt change last year.

 

[Park]

From what I understand the radiator corrodes and allows the to fluids to mix. The factory radiator is actually two cooling systems and it utilizes the coolant from the radiator to help cool the tranny. In my mind this is actually a more efficient setup than just slapping on an external cooler. I am buying a new radiator soon and I plan on ditching my external tranny cooler. I doubt it does as good a job as the stock one.

Basically just keep your radiator maintained. I think the milkshake occurs when people neglect to replace radiators

 

[Jhelms]

From what I understand the radiator corrodes and allows the to fluids to mix. The factory radiator is actually two cooling systems and it utilizes the coolant from the radiator to help cool the tranny. In my mind this is actually a more efficient setup than just slapping on an external cooler. I am buying a new radiator soon and I plan on ditching my external tranny cooler. I doubt it does as good a job as the stock one.

Basically just keep your radiator maintained. I think the milkshake occurs when people neglect to replace radiators

That is what I am thinking. Observing how the radiator and cooler is actually assembled, I can only see corrosion causing the milkshake. This would come from acidic coolant / electrolysis (same thing that happens to an anode rod in a hot water heater - except an anode rod is designed to corrode so the tank does not)

Would really like to see someone with the milkshake do a teardown.

I really just want to get to the facts on the failure and why it happens. I DO think an aftermarket cooler is a good idea and will not hurt anything. But I also think most of this is unnecessary unless I see proof of the transmission cooler core failing in a fashion OTHER than corrosion.

 

[cashmoney]

There's no reason to replace a radiator on a properly maintained system. And several folks here have shown the external coolers do just as good of a job as the factory one. Maybe even more so because if the coolant starts heating up it can heat up the trans fluid and vice versa.

 

[Jhelms]

Coming from years of manufacturing experience, my theory is defective radiators that were possibly produced poorly. It could come down to a batch of radiators that were rushed through the process for cost sake. Ive seen management cut corners on everything to hit their bottom line and keep a job. A disgruntled employee maybe? Who knows. Inferior products almost always come down to one dumbass making hasty decisions. Just what I think.

Agreed, but I have not seen any proof yet of a physical failure of the core which could be a possibility.

On another note, crappy electrical systems / poor grounding also contributes to electrolysis in the coolant system. A standard maintance item should be to clean all the ground points / use die-electric grease under the ground bolts in every place you find (after you clean the metal with de-oxit or lectramotive / a wire brush or wheel)

 

[jgue467]

Pink Milkshake is not just for 4Runners

Several other manufacturers use the same concept of trans cooler built into the engine radiator - they all fail (Nissan xterra, pathfinder and frontier for example) at different rates, some 5% others higher. Not sure what the T4R failure rate is.

any body ever crack-opened up OEM rad, if not, here we go! - YotaTech Forums

Difficult to say what the root cause it, lack of maintenance, poor seal materials, metallurgy or something else. :cowboy:

 

[Jhelms]

There's no reason to replace a radiator on a properly maintained system. And several folks here have shown the external coolers do just as good of a job as the factory one. Maybe even more so because if the coolant starts heating up it can heat up the trans fluid and vice versa.

That is where my mind is at all on this too. I think the (add an aftermarket cooler) is overblown. However, if you do not know the service history on the car or if one has neglected the cooling system, it would be WISE to change out the radiator preemptively.

On the other topic, yes, as tranny temps rise, they can cause coolant temps to rise... which in turn let the tranny temps rise more. They can fight each-other. Another reason it is wise to clean the condenser and radiator on a regular basis / keep them efficient.

 

[Jhelms]

Several other manufacturers use the same concept of trans cooler built into the engine radiator - they all fail (Nissan xterra, pathfinder and frontier for example) at different rates, some 5% others higher. Not sure what the T4R failure rate is.

any body ever crack-opened up OEM rad, if not, here we go! - YotaTech Forums

Difficult to say what the root cause it, lack of maintenance, poor seal materials, metallurgy or something else. :cowboy:

Those are interesting photos. They tend to lead one to think the failure COULD occur at the connection points. Basically the O-ring or connector fail on the tranny cooler portion which allows atf to flow within the radiator. This would be pretty easy to diagnose however / inspect by simply removing the connectors.

 

[LittleCaesar]

I'd say bad manufacturing process, where something goes awry or the tolerances aren't tight enough.

In six years I have read stories where members have had the milkshake as early as 80,000 miles. Many go the lifetime of the 4runner with the original radiator, no problem. Considering the Tacoma 5vz has had little or no instances of such, and it uses a different radiator.

For me in 2009 it was either spend $150 on a new radiator, hoses, t-stat, etc. or taking a risk of having to shell out at least $2000 for a used tranny and that wasn't including labor so I chose the former and haven't regretted it once.

 

[azcat90]

Tap water instead of distilled?

Could it be topping off your radiator with the garden hose?

 

[nevada]

From what I understand the radiator corrodes and allows the to fluids to mix. The factory radiator is actually two cooling systems and it utilizes the coolant from the radiator to help cool the tranny. In my mind this is actually a more efficient setup than just slapping on an external cooler. I am buying a new radiator soon and I plan on ditching my external tranny cooler. I doubt it does as good a job as the stock one.

Basically just keep your radiator maintained. I think the milkshake occurs when people neglect to replace radiators

I don't want to derail this thread too far off topic,

but how can that be more efficient? you are using 180-200 degree coolant to "cool" the ATF.
how low will a good system drop the coolant temp? down to 155 or so? so at best the atf is being cooled with 155* liquid.
it seems as though ambient air being drawn across the external cooler would do a much better job.

I believe manufacturers do it to save time and money in production, not because its better...

 

[D Farms]

It would be good to see the inside of a pink milkshaked radiator. the 80 series also runs through the main radiator, but only to regulate the temperature, it does actually have a transmission radiator that it passes through first before it goes into the main one. Heres what I think happens: the fluid is hot when it enter the radiator, possibly causing corrosion to occur more quickly, and this over time causes it to fail. this is not common on the landcruiser, because the fluid has been cooled before it gets to the main radiator.

 

[Jhelms]

I don't want to derail this thread too far off topic,

but how can that be more efficient? you are using 180-200 degree coolant to "cool" the ATF.
how low will a good system drop the coolant temp? down to 155 or so? so at best the atf is being cooled with 155* liquid.
it seems as though ambient air being drawn across the external cooler would do a much better job.

I believe manufacturers do it to save time and money in production, not because its better...

Azcat90 - Indeed :cheers: so many people that do not understand cars or coolant systems just drop in tap water. Makes me sick.

Nevada - ATF is designed to operate at the same temperatures as the engine. Generally around 190-210. However nothing bad about running it a little cooler / in the 180's which can be done by using a lower temp thermostat (if using the stock radiator / tranny cooler combo)

Having the core totally submerged in fluid is a VERY efficient way to cool the tranny fluid vs air. This is the same effect as using a tiny ATW intercooler VS. a huge ATA intercooler in boosted applications. Similar or same cooling capacities, drastically different sizes. Does not matter if the coolant is already at 190-200, it will help hold the transmission fluid at exactly 190-200.

LittleCaesar - I still am not seeing a manufactures defect here unless we start to see tank ruptures with no corrosion (still possible but have not seen it) This is the point of this post. I am not looking for conjecture, but facts.

 

[csp]

A manufacturers defect would include faulty/cheap materials prone to corrosion, so a tank rupture isn't the only proof of such.

Glad I don't lose sleep over stuff like this.....

 

[Jhelms]

A manufacturers defect would include faulty/cheap materials prone to corrosion, so a tank rupture isn't the only proof of such.

Glad I don't lose sleep over stuff like this.....

I agree, however aluminum is quite prone to electrolysis / corrosion and that is what a good portion of our engine is made from Degraded coolant will eat passageways in the heads, water pump and all over.

Anyways - really looking forward to taking a good look at a radiator that has had PMS lol. Hopefully there is an AZ member that can speak up which has one. Or someone will pull the tanks off theirs to see where the failure occurred.

 

[StreetCreeper]

All these failures that are reported always seem to be the OEM radiators, but I rarely if ever hear of an aftermarket radiator failing. I wonder if it is in fact a OEM Toyota flaw or quality control issue, or just that aftermarket radiators simply haven't been on the truck long enough to start failing in numbers that people take notice?

 

[Jhelms]

All these failures that are reported always seem to be the OEM radiators, but I rarely if ever hear of an aftermarket radiator failing. I wonder if it is in fact a OEM Toyota flaw or quality control issue, or just that aftermarket radiators simply haven't been on the truck long enough to start failing in numbers that people take notice?

Could go a lot of ways... need to crack open a few milkshake radiators and pinpoint the failure. Will point straight away to neglect, physical failure/defect or?

 

[csp]

I agree, however aluminum is quite prone to electrolysis / corrosion and that is what a good portion of our engine is made from Degraded coolant will eat passageways in the heads, water pump and all over.

#1 Contrary point - wall thickness

#2 Contrary point - "aluminum" can come in any number of alloys and grades of quality. You can't put it all into one basket just because a magnet doesn't stick to it.

 

[Gadgetguy]

This has happened to a lot of other manufacturers as well, most companies use a shared radiator to cool the trans. We just don't know about the other ones as widely because we aren't on other sites. I frequented a Fullsize Bronco site for a while and it happened to plenty of them. It does boil down to maintenance usually.