Separate Trans cooler entirely? (1 Viewer)

[Beau]

Not sure if this topic has been discussed before, but on my prado I bypassed the stock factory trans cooler (Radiator one) and it's run completely through it's own independent cooler up front.

Do people do this on these trucks? Thoughts are:

Will the trans run cooler or warmer? Should be better not dealing with the water temp? This is what I saw on my prado. Should also put less cooling stress on the main radiator although this could be balanced back by the additional heat the trans cooler now passes back.

Also less change of ATF and Coolant mixing in the event the internal radiator fails. If the separate cooler ever failed, you could temporarily run the lines back the original cooler. ..

The only downside I see is that in colder climates, the trans will take longer to get up to temp.

 

[abuck99]

There is an external cooler on the 100 series.

 

[cjmoon]

Trans runs cooler almost too cool can cause sloping at lower temp in the winter. I don’t run it through my radiator but cover the cooler during the winter to help it warm up.

 

[Beau]

I know there is a separate cooler. But it runs in series with the main radiator cooler at the bottom. My question is, is it common to just run the trans on a separate circuit completely.

 

[Beau]

Trans runs cooler almost too cool can cause sloping at lower temp in the winter. I don’t run it through my radiator but cover the cooler during the winter to help it warm up.

What was your reasoning bypassing the rad? Did you see lower trans temp?

 

[abuck99]

I know there is a separate cooler. But it runs in series with the main radiator cooler at the bottom. My question is, is it common to just run the trans on a separate circuit completely.

Not common- not necessary.

The trans cooling design on the 100 series is very good as it stands. Typical trans operating temps range from 135F to 160F depending on climate, OAT, and towing or mountain climbs. Other Toyota platforms seem to run closer to 190F.

The heat exchanger in the bottom radiator tank helps to get trans fluid to operating temp faster- I dont see any reason to bypass it.

 

[hoser]

The mixing coolant with ATF (aka pink milkshake) is not an issue with the 100 series. Don't bypass.

 

[AlpineAccess]

The mixing coolant with ATF (aka pink milkshake) is not an issue with the 100 series. Don't bypass.

It's pretty interesting to me that both the 4R and the Tundra had this issue and the 100 ducked it.

 

[hoser]

Denso radiator vs T.Rad radiator

 

[nissanh]

You have a prado which shares the same frame/engine/tras as a hilux surf or 4runner. Over at 3rd gen 4runner we suggest NOT to by-pass the radiator due to all above mention issues. Replace any aftermarket radiator every 10 years to avoid pink-milkshake (coolent and ATF mixing). The factory radiators in these trucks ae well made no one replace it even after 20+ years. Due to its age, the only issue we find is corrosion in the ATF cooler in the bottom tank leading to mix coolant to ATF.

 

[Beau]

You have a prado which shares the same frame/engine/tras as a hilux surf or 4runner. Over at 3rd gen 4runner we suggest NOT to by-pass the radiator due to all above mention issues. Replace any aftermarket radiator every 10 years to avoid pink-milkshake (coolent and ATF mixing). The factory radiators in these trucks ae well made no one replace it even after 20+ years. Due to its age, the only issue we find is corrosion in the ATF cooler in the bottom tank leading to mix coolant to ATF.

Got it! Seems like these things were built better then, that's reassuring. I know 4runner member suggest not to by-pass it but I live in florida and when towing on my standard setup, the trans warning light would kick in. So I bypassed the rad and have never seen temps above 180 again. Sure, if I lived in a colder climate I would probably leave it factory but for a hot climate this has worked great, and has been this way for 5 years now without a problem.

 

[nissanh]

Did you import a prado to FL? What year prado is it? Left hand drive, manual and diesel? Someone is getting jealous here!
Correct you can have a transcooler externally if you live in hot areas. I am in West TX, which is hot but in Dec-February, it is freezing cold so I cannot by-pass the radiator cooler in my 3rd gen 4runner.

 

[Beau]

Did you import a prado to FL? What year prado is it? Left hand drive, manual and diesel? Someone is getting jealous here!
Correct you can have a transcooler externally if you live in hot areas. I am in West TX, which is hot but in Dec-February, it is freezing cold so I cannot by-pass the radiator cooler in my 3rd gen 4runner.

Yes, I imported the truck over when I moved to Florida from England about 5 years ago. It's a 1997 Prado RHD Diesel 1KZT-E. At present, I believe it's the only prado diesel in the US. Honestly wish they sold the diesel lump over here for the 100 series, the torque from diesel just allows for such easy driving. I personally find the 2uz a very lazy engine compared to me 1KZ.

 

[DuckLN]

It's pretty interesting to me that both the 4R and the Tundra had this issue and the 100 ducked it.

an issue? Never heard of it myself.

 

[AlpineAccess]

an issue? Never heard of it myself.

Same pink milkshake issue noted earlier. Radiator barrier between coolant and ATF cracking and blending fluids.

 

[Njck22]

Yes, I imported the truck over when I moved to Florida from England about 5 years ago. It's a 1997 Prado RHD Diesel 1KZT-E. At present, I believe it's the only prado diesel in the US. Honestly wish they sold the diesel lump over here for the 100 series, the torque from diesel just allows for such easy driving. I personally find the 2uz a very lazy engine compared to me 1KZ.

You can’t tell us all about it and not post a picture!

 

[Beau]

 

[Beau]

 

[Joe422]

Been watching my ATF temps with a ScanGauge2, and even on trails, it hasn't seen any alarming temps.
Not sure an ATF cooler upgrade is necessary yet...

However, keeping the ATF clean and fresh is probably a good thing to keep on top of~