mt_goat

You may be right, but another possiblity is stress cracking. We need someone with a failure to cut open a radiator and inspect the thing. If one of you guys replaces the rad with a new one please don't just throw the old one away without opening it up for some pics.

ARB1977

Just courious what kind of setup are on the 2005+ Taco's? They do have a seperate cooler but does anyone know if they use the radiator as well?

97ltd4x4

Oh,and I put this one in mine,well its a tight fit,but I got it in there,It's a monster... also had to double clamp the hoses,they were a little loose on the cooler,because of the lines I used..

Tru-Cool LPD 4589


http://www.bulkpart.com/Merchant2/me...roduct_Count=1

But I used the hayden's on everyone else's I have done......

Maj

I sent an email to bulkpart.com and they thoughtfully replied. Keep in mind that they are not necessarily experts about our 4Runners but here are their responses (in red) to some questions (in italic):

I have a '97 Toyota 4Runner that is prone to have a radiator failure that results in cooling and transmission fluid mixing. A number of us on an internet board (yotatech.com) have some questions regarding aux tranny coolers:

1. Is plugging the tranny portion of the stock leaking radiator and bypassing with an aux cooler advisable?

Not normally, since the cooler is already leaking internally, it may develop other leaks / fatigue spots faster and leak externally also.

2. What are the downsides associated with having only an aux cooler in terms of overcooling the fluid during cold weather? Poor lubrication, bad shifting?


Electronic transmissions will not shift properly when cold -
In extreme cold conditions -10 degree they can cause slow lube conditions. .

3. What ambient temp would be too cold to operate without a thermostat/bypass for an aux-only cooler?

Mfg. recommends a Bypass installed in areas where it stays below 30 degrees

4. If the stock radiator cooler is retained, what is the best way to plumb the cooler?

a. tranny --> aux cooler --> radiator --> tranny = WRONG

b. tranny --> radiator --> aux cooler --> tranny = CORRECT

I do not suggest mounting it backwards (A)






# 4589
Tru-Cool LPD, thick cooler & standard installation kit
On Special!
Truck & heavy duty to 24,500 GVW
Low pressure drop cooler , 8 x 11 x 1 1/2 thick...info->





This is the minimum size cooler I would suggest if you are going to By-Pass the Radiator

"Tru-Cool" self regulating coolers - it's the oil that regulates the cooler.
That is the principle behind the revolutionary new TRU-COOL SR series of self-regulating transmission oil coolers.
Thicker oil that is below the ideal operating temperature bypasses the cooler through the upper two plates.
When the temperature rises, it becomes thin enough to pass through the entire cooler and receive TRU-COOL's superior heat transfer efficiently, automatically.


And use a By-Pass if your area is always cold in winter

# 708-4739
Remote external thermal bypass
External thermal bypass for large coolers used in cold climates (32 degree -).
Installs in cooler line. Includes bypass only!
Use on 5/16" & 3/8" line sizes ONLY!!
Opens fully at approx. 180 +- ...info->

hector200sx

group buy on trans coolers lol

dgz32

Well, dang. I have the 4454 on order from them right now. Wonder if I should change it to the 4589...???

mt_goat

I wouldn't, those thick coolers are much harder to fit in tight places. My 4454 cools very well, I run a trans temp gauge and have monitored the ATF temps over 2 hot summers. I don't tow anything but I've loaded it down pretty good and hit the mountain passes hard with a supercharger.

dgz32

I saw that you'd had much success w/yours...which influenced my decision on the 4454. So I'll stick with that. Is it possible to over cool the transmission? Or has this been covered already...?

mt_goat

Yes and yes But its pretty hard with the bypass coolers like these. It would have to be freezing temps.

dgz32

Hehe, thought I'd remembered seeing something. Nothing to worry too much about here in Georgia, I don't guess. Regardless, looking forward to getting the cooler on so I can sleep at night.

Smokey

Does this failure seem to be seen more with people that tow, carry heavy loads, run aggressive trails, etc? Or is it susceptible under normal highway use too?

I have not looked at all the failure post, but does anyone have an average mileage estimate at time of failure between each occurance?

Chris

hector200sx

i would say most are over 75k

Meterpig

It is interesting to note that the aftermarket guy is recommending a heat transfer via liquid which is exactly what is happening with the current stock setup.

Negative ten is very cold. Most folks haven't been in that type of cold. However, if you go with an air cooler, it makes sense to spend the extra dough for a bypass.

mpavolka

I work for a company that builds and sells aftermarket radiators and I have only heard of this happening to one or two of our radiators, and neither was a Toyota. It seems that this is more of a defect with 4Runners. Has anybody even had it happen with a Tacoma?

KZN185W

iTrader: (1)

anyone familiar with the B&M oil cooler? or has bad or good experience with?

http://store.summitracing.com/egnsea...5&autoview=sku

Mtn Mike

iTrader: (1)

Very interesting. After reading this thread, I am planning to install the Tru-Cool LPD cooler in my 2000 4 Runner. A few questions for those with experience:

1) I live in a cold climate ( stay's below 32F all winter). Will I need a thermal bypass valve to maintain proper ATF temperature with the Tru-Cool LPD 4454? (http://www.bulkpart.com/Merchant2/me...roduct_Count=2)

If so, which bypass valve should I get?

2) Should I plan to install a ATF temp gauge at the same time? If so, where inline?

3) Do I need to drain my ATF fluid before unhooking the lines? Will I need to worry about air in the ATF lines after reattaching them?

Thanks for the info!

Mike

97ltd4x4

1. No Tru-Cool LPD have them built in.
2.I guess if you want to put one in I would do it as colse to the trans exiting cooler line,although I think this would be unnecessary if the cooler is mounted behind the grill in the airstream and infront of the fan.
3.No draining ,you will loose some from the lines/radiatior cooler,maybe several ounces...Do not need to worry about air..Once cooler and lines are installed,start vehical,check for leaks,and fluid level..Might have to add 1/2 quart of fluid depending on the size of cooler,how long and diameter of lines.

mt_goat

#3, no need to drain it, either way you'll get some ATF spillage. It helps if you're fast. I've got some little rubber plugs (from hardware store) I use sometimes to minimize spillage. Don't worry about air in the lines.

#2, I think we covered that pretty well on page 2, might go back and reread that section.

mt_goat

Hey 97ltd4x4, it seems like maybe you are a Toyota master tech. Do you know if the newer Tacomas or Tundras use an external ATF cooler? I saw one in Colorado this summer that had an ATF cooler behind the grill and the guy said it came stock like that and according to him it didn't have an ATF cooler in the radiator. Do you know for sure?

97ltd4x4

Yes,I used to be a Toyota master tech,as well as Lexus Pro...But,I have no idea about the newer stuff,I hung up my wrenches about 6yrs ago(still do some work on the side)..I know for sure the landcruisers back to 84'ish.. all the way up to the 97's maybe still on the newer ones after 97',I can't remember...they only had an external trans cooler,nothing in radiator..I also remember all the auto MR2's auto,just had an externat cooler,no radiator cooler..I guess because of mid engine,sending fluid all the way up front,then back was too ineffeciant.