broken oil cooler from auto-gearbox

[BorS Junior Member Find all posts View Profile Close BorS]

Hello all,
I own a VZJ95 with a 3.4V6 from 2000.
I was advised to replace the radiator(with build in oil cooler) for the auto-gearbox.
The story is that there are a lot of problems with the oil cooler. It will internally going to leak and then there will be ATF in the cooling system and water in the gearbox.
That will give problems on the cooling system, the rubber hoses do not like ATF, and also there will be water in the gearbox.... also not good.
It is specially with diesels. But the radiator of a petrol engine is the same as a diesel.

There are not many Prado’s in the Netherlands, so the dealer cannot really advise me.

Anyone ever heard of this? Should I replace the radiator? (a new radiator is much cheaper than a rebuild auto transmission)
Let me know what you think

[glen_ep Addicted PP Member Find all posts View Profile Close glen_ep]

Having a combined ATF and coolant radiator is certainly not ideal, BUT, I haven't heard of the issue you speak of. Yes I've heard of the radiator failing/stretching/leaking with age, due to it's construction materials, but the end symptoms were only overheating. I haven't heard of such a big failure to cause cross-contamination and auto box failures.

I would only replace it if there's a very clear indication of a failure or you're about to set off on a very big trip with very few repair options along the way.

[williade Avid PP Poster! Find all posts View Profile Close williade]

Did the person who advised you of this have a new rad to sell you? Because to say this is a big problem with Prado's is a bit rich by any measure. Short of getting a stick through the rad or corrosion due to neglect I don't think there is any chance of ATF mixing with your coolant.

[BorS Junior Member Find all posts View Profile Close BorS]

Having a combined ATF and coolant radiator is certainly not ideal, BUT, I haven't heard of the issue you speak of. Yes I've heard of the radiator failing/stretching/leaking with age, due to it's construction materials, but the end symptoms were only overheating. I haven't heard of such a big failure to cause cross-contamination and auto box failures.

I would only replace it if there's a very clear indication of a failure or you're about to set off on a very big trip with very few repair options along the way.

Yes "it" was about stetching with age.
I heard it some months ago. Looked on the internet sinse... and did not find anything about it. Like you say, it can happen... but not often.

Did the person who advised you of this have a new rad to sell you? Because to say this is a big problem with Prado's is a bit rich by any measure. Short of getting a stick through the rad or corrosion due to neglect I don't think there is any chance of ATF mixing with your coolant.

Yes he could sell me one. But I "know" the guy. I did buisness with hem before... no problems.... but now I am starting to think.....


For now I will stick with checking the waterlevel and check it for oil.
Thank you

[Bounder Junior Member Find all posts View Profile Close Bounder]

Might be rare in Aus, but in the UK it has happened quite a lot.
The combination ATFcooler/radiator leaks and lets coolant into the autobox causing damage.
Lots of talk on UK forums about it.
Heres one post http://www.tlocuk.co.uk/forums/viewt...ilure&start=15

[williade Avid PP Poster! Find all posts View Profile Close williade]

That's interesting. I wonder if Australia got different rads to Europe? Maybe to cope with the hotter climate?

Rather than replacing the rad, just do what was mentioned in Bounder's link and bridge the input and output of the stock ATF cooler and install an after-marker AFT cooler. You'll get much better cooling performance for the transmission than stock too.

[Derb Senior Member Find all posts View Profile Close Derb]

Hi Fellas. Mentioned this one to my young fella (toyota mechanic) and he had never heard of the problem. Sounds like your serviceman is a bit sharp. I would go with Williade if this is preying on your mind. These aftermarket coolers are a doddle to fit at home and do the business. Cheers.

[BorS Junior Member Find all posts View Profile Close BorS]

Might be rare in Aus, but in the UK it has happened quite a lot.
The combination ATFcooler/radiator leaks and lets coolant into the autobox causing damage.
Lots of talk on UK forums about it.
Heres one post http://www.tlocuk.co.uk/forums/viewt...ilure&start=15

Thank you, maybe there is indeed a diverence between the austalian and European conditions... I Yesterday found a European Landcruiser forum.
And now yet another new forum (for me). I will search them for this problem.

Wolliade, I am not a fan for this sort of seperate stuff.

Another question. A new Toyota radiatar is about €450,- , a "brandless"(European made, not chinees) one is about €150,--
What do you think.. saves a lot of money.

[glen_ep Addicted PP Member Find all posts View Profile Close glen_ep]

A separate oil cooler is definitely the go. I'm not sure what kind of harsh conditions you experience over there, but here during summer, it's common to see cars on the side of the highways due to overheating. The problem with this dual coolant/ATF radiator is that if a hot engine isn't noticed early enough, it'll also overheat the ATF, and cause damage to your transmission. So again, for Australian conditions, a separate cooler is definitely the way to go.

[Bounder Junior Member Find all posts View Profile Close Bounder]

Bors
I would seriously consider fitting a seperate ATF cooler, its not much work and it avoids the whole problem of ATF fluid and coolant mixing.
If you replace the Rad, I would use a Nissens brand one, they are Danish and have a good rep.
Yours is petrol so I can't comment with any authority but the Diesel autos definately have issues with the combined rad.
I have a manual diesel and have never had any problems since I noticed the temp needle moving and replaced the Rad 5-6yrs ago.

[ken2m Junior Member Find all posts View Profile Close ken2m]

Might be rare in Aus, but in the UK it has happened quite a lot.
The combination ATFcooler/radiator leaks and lets coolant into the autobox causing damage.
Lots of talk on UK forums about it.
Heres one post http://www.tlocuk.co.uk/forums/viewt...ilure&start=15

Could be the FREEZING cold conditions in the U.K. causing the radiator to freeze causing cracks in the auto trans cooler from being encased in ice. In any case keep the coolant concentration to the recomended level to keep the freezing point as low as possible.

[BorS Junior Member Find all posts View Profile Close BorS]

Bors

If you replace the Rad, I would use a Nissens brand one, they are Danish and have a good rep.

Thank you all. I replaced the radiator and cooler, with a new one from Nissens. The quality looks good and the price was 1/4 of the Toyota one.

Thank you all for the advice.

[echo Lurker Find all posts View Profile Close echo]

I replace the radiator in mine around 190k. When it was changed the auto fluid hose was just touched it just fell off the radiator.
The worst bit was it was only in at a Toyota dealer 1 week earlier on for a major service & they didn't say anything about it *shrug*

[glen_ep Addicted PP Member Find all posts View Profile Close glen_ep]

For future reference, if anyone is considering a separate oil cooler, please read this post first:

http://www.pradopoint.com/showthread...ler#post305268