Transmission cooler: to by-pass the radiator or not to by-pass it

[TX4Running]

Radiator design

Drcoffee,
Thanks for the reply. I'll be looking to do this real soon with 180K on the original radiator.
Thanks again.

 

[TX4Running]

New Radiator Install

I am looking into the B&M cooler as well as a new Koyo 1998 radiator. Does the radiator come fully constructed? Meaning I won't need to install any o-rings or "caulking" as it's shown in the service manual? I should be able to disconnect hoses, unbolt, and then reverse, correct?

 

[Qyota]

The 1998 radiator is ready to install. Mine came with new hardware, too.

 

[TX4Running]

Radiator Install

Qyota,
Thanks for the prompt reply. For these installs, must the A/C condenser be removed first? And, on the tranny cooler have you found an easy method for securing it? Or, just use zip ties and small cushioning pads like I've seen in one of the posts? Anyone have any pics and/or directions for mounting the cooler?

 

[jkoni426]

Qyota,
Thanks for the prompt reply. For these installs, must the A/C condenser be removed first? And, on the tranny cooler have you found an easy method for securing it? Or, just use zip ties and small cushioning pads like I've seen in one of the posts? Anyone have any pics and/or directions for mounting the cooler?

I just used the provided zip ties and pads to mount mine, no need to remove the condenser. Here's some pics of my install:

Don't really understand why some people don't bypass the stock cooler, the whole point of this install imo is eliminating the possibility of the milkshake happening.

 

[Drcoffee]

I have a simple question for Drcoffee: What are your transmission temps?

Just for giggles, I went back to re-read the thread. Still makes me laugh.

To answer your question, I finally added a cooler in series and the temp gauge. With an ambient temp of 70* my temps run from 135-155 while moving and 165* while stuck in traffic. That is the sweet spot for prolonged trans fluid life. Without the extra cooler, I would suspect temps were near 180-200+. I can only imagine what it would be while towing.

It works for me.

 

[Luke the Dog]

I just spent 45 minutes and read this whole thread...aside from my head about exploding, I did realize there are salient points mixed in with the rest of the crap!

These are my findings:

1. I want a T-shirt and/or bumper sticker with Dr. Coffee's avatar on it.

2. I might install a B&M cooler now, bypassing the radiator for now (because my truck won't explode if I do), then buy a new radiator a little ways down the road and run them in tandem (because my truck won't explode if I do)...

 

[quicksilvr]

^Haha, great points Luke.

I was going to mention that my truck exploded last week, due to my transmission cooler bypassing the radiator, but figured it would make me look bad.


lol. :cheers:

 

[Drcoffee]

Okay, its been a while since the incident so I can just bring up a little irony in all this. After all the crap our friend tbst has offered through this thread, this is his truck. Ironic really

http://www.toyota-4runner.org/3rd-gen-t4rs/114683-what-f-7k-just-happened.html

Luke, just because you are taking the transmission out of the coolant loop doesnt mean your radiator won't break and overheat. If its old, you should replace it now. Its the threaded coupling that corrodes and breaks. We'd all hate to see it give out and leave you stranded on the road or trail.

 

[Luke the Dog]

I'd rather be stranded with a cracked rad than stranded with a cooked tranny, I'm going to do the B&M first and then replace the rad in a year or so...they're both cheap insurance

 

[dyehl]

Noob here. Now, I am confused. I thought the whole point of adding the external cooler was to bypass the radiator so that you could avoid the milkshake. The only other reason I see to add one is for towing purposes or if you have issues with overheating.

I live in Colorado and make frequent trips to the mountains. It can be very cold in the winter and very hot in the summer. I don't tow anything and my truck is not lifted nor do I take it offroad much.

I just bought a new koyo a1998. Do you think I should just stick with that or add an external cooler and run it in line or bypass it.

Thanks for the advice in advance.

 

[dbsoundman]

Noob here. Now, I am confused. I thought the whole point of adding the external cooler was to bypass the radiator so that you could avoid the milkshake. The only other reason I see to add one is for towing purposes or if you have issues with overheating.

I live in Colorado and make frequent trips to the mountains. It can be very cold in the winter and very hot in the summer. I don't tow anything and my truck is not lifted nor do I take it offroad much.

I just bought a new koyo a1998. Do you think I should just stick with that or add an external cooler and run it in line or bypass it.

Thanks for the advice in advance.

This thread has gotten to be quite a mess, but in general, the reason the radiators have this issue in the 4Runner is that they are not mechanically isolated at all from the chassis, so over time the bumps of the road, combined with corrosion, can cause the threads inside the radiator to strip, and fluids to start mixing. Now, the corrosion may in fact be caused by the use of non-Toyota ATF and other factors, but I also live in CO, and my plan is to replace the radiator and add a cooler, and only use the cooler for the transmission. Unless you're doing extreme driving in extreme places (like Arizona), you should be fine with this setup (I hope I will!).

 

[dyehl]

Awesome, thanks for the advice.

 

[zooroadbaja]

Mods need to make a sticky about this radiator, B&M situation. Way to many post in the past few days about this.

 

[Limbwalker]

Holy hell. this thread. :repuke:
First off, thanks everyone for the entertainment, and the bits of useful info!
However, Im back to square 1 in my decision. Actually, no... I think Ive come to a conclusion.
I live at 6300 feet where temps in the summer can be 100* while hitting -40 windchills in the long winters... Supercharged with bigger tires, lift, winch bumper etc, so its heavier than stock by a fair bit. My drive to work is short (for now) giving little time for tranny to warm up, BUT, I also frequently load this thing with camping gear for long hauls over 13000' mtn passes followed by hours of low range off roading. And sometimes pull a utility trailer with it.
So basically, Im putting this thing thru everything it was made for imaginable, and then some. 135k. I bought it at 114k 5 years ago, and havent flushed the coolant yet...
I bought a Hayden 677 cooler which I had originally planned to install bypassing the Rad.
But after this thread and many others going back and forth, back and forth, I think the thing FOR ME in my circumstance is to also replace the Rad (bummer, more cash) and install the cooler in series.
This just makes the most sense to me using the vehicle the way I do, in the environment I do.
I dont want a bunch of expensive gauges giving me more OCD than I already have about these things, I just want to set it/and forget it.

 

[RockyMtnYota]

Nice proper post there sir. Good use of caps! Haaa! I think you are looking at this correct, its what you are comfortable with on your own setup. Never a "right" set up just what you think will work for your situation. As long as you are making some changes/repairs can't be too bad of a thing. I def agree with the extra gauges...I would wreck pretty damn quick...always staring at them looking for changes :fear:

 

[19963.4lsr5]

I'm looking on Craig's list for someone parting out a 94 to 98 dodge ram with the cummins.

They have a external heat exchanger under the turbo. Coolant on one side and trans fluid on the other. And it's pretty large.

I was thinking of putting it in series with the existing engine oil coolers coolant lines or tapping off the heater core lines Pryor to the cutoff valve.

I'm thinking the engine oil cooler line going to the water pump housing is a return. I could tee into that as well for the return and supply it from the upper heater line.

Those heat exchangers don't fail. Unlike the ones on the 98 1/2 and newer engines where they changed location and design.

 

[Drcoffee]

I'm looking on Craig's list for someone parting out a 94 to 98 dodge ram with the cummins.

They have a external heat exchanger under the turbo. Coolant on one side and trans fluid on the other. And it's pretty large.

I was thinking of putting it in series with the existing engine oil coolers coolant lines or tapping off the heater core lines Pryor to the cutoff valve.

I'm thinking the engine oil cooler line going to the water pump housing is a return. I could tee into that as well for the return and supply it from the upper heater line.

Those heat exchangers don't fail. Unlike the ones on the 98 1/2 and newer engines where they changed location and design.

The best you can hope for is somewhere north of the coolant temperature. And can anyone tell me how hot that might be?





A: Too hot is the correct answer.
:doh:

 

[Brique]

I finally reached the end of this post. It's 4am and I'm way past my bedtime.

Holy hell.

Think I'll probably do both a new radiator and external cooler. Gonna bypass though. Aside from the random coyote hit, there's also the possibility of a defective radiator causing the pink milkshake when the thing's still newish.

 

[19963.4lsr5]

The best you can hope for is somewhere north of the coolant temperature. And can anyone tell me how hot that might be?





A: Too hot is the correct answer.
:doh:

Then why is there an existing oil cooler if it will make engine oil too hot. Or are you saying it will be too hot to cool trans oil?