Transmission temps after bypass questions!

Amirocassar said:
Yes that is true, but if the return line is on the top then I'd have to rely even more on pressure or the ATF to reach the top andgo back to the tranny. See my point?
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I don't think you see my point. For a given location of the fluid cooler, the fluid must travel the same amount of distance up and down. If you put the return line on the bottom, the fluid will do more of its uptraveling in the feed line. If you put the return line on top, the fluid will do more of its uptraveling in the cooler itself, but it cannot go up without going down and vice versa. There is no "gravity assist" to the overall fluid circuit because the start and end points of the circuit are at the same elevation (the transmission), and assuming no weird 1way valves or blockages, no difference in efficiency of the system based on your feed and return line locations.

I'm definitely interested to hear more about other reasons to locate the feed on top or bottom. Both the theories presented in this thread make their own kind of sense and I'd love to see this get hashed out.
 
Drcoffee said:
The fluid goes in the top and out the bottom of the cooler. Because of the valves in the tranny, the fluid cannot drain back thru the feed line. In cold weather the trans fluid will gel or freeze in the trans cooler causing back pressure. You have it right. Send it in the top port and out the bottom so when you shut down, the fluid drains back to the trans pan.

Now the other issue you said the hose was too tight. The B&M coolers come with 11/32" hose. You want 3/8" hose. The smaller hose is something like 15% smaller by area, making your transmission fluid pump work harder to move the fluid an even longer distance than it was designed for. The ports on the cooler are 3/8".
Dont replace it with anything other than trans fluid hose. Fuel line and vacuum line with breakdown with ATF.

Not really sure where you are but the real test is in warm weather. It will take longer to heat the trans fluid if you bypass the radiator. Also, 20 minutes is not long enough to test it. You need to reach the point of heat soak. Where the trans cannot radiate anymore heat and then you will find out if your cooler is sufficient to keep the temps in the correct range. 130-170*
The main problem with bypassing the radiator is now you need to be ever vigilant monitoring your trans temps 24/7/365. Have fun!
:rofl:

For the record, I prefer buying a new radiator and keeping it in series with the cooler.
Transmission -> Radiator -> Cooler -> Transmission

http://www.toyota-4runner.org/3rd-gen-t4rs/107129-transmission-cooler-pass-radiator-not-pass.html


The 70268 is only 3/4" thick and far far tooo small for your vehicle when you bypass the radiator.
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Your wrong but its not my problem. I look forward to your tranny swap thread:gun5:
 
KidVermicious said:
I don't think you see my point. For a given location of the fluid cooler, the fluid must travel the same amount of distance up and down. If you put the return line on the bottom, the fluid will do more of its uptraveling in the feed line. If you put the return line on top, the fluid will do more of its uptraveling in the cooler itself, but it cannot go up without going down and vice versa. There is no "gravity assist" to the overall fluid circuit because the start and end points of the circuit are at the same elevation (the transmission), and assuming no weird 1way valves or blockages, no difference in efficiency of the system based on your feed and return line locations.

I'm definitely interested to hear more about other reasons to locate the feed on top or bottom. Both the theories presented in this thread make their own kind of sense and I'd love to see this get hashed out.
Click to expand...

Yeah I see your point now, but I also see mine. I'm glad you see the same thing. I'm kind of curious which would be better.
 
Amirocassar said:
Yeah that's why I followed science. Makes no sense whatsoever to do it the opposite way. However, I do disagree with that my cooler is too small. Countless people have done it with the 70268 and haven't had any problems.
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your attempt to apply logic and intuition is misplaced in this instance. The fluid is pumped through the system and requires no assistance from gravity to circulate. this is been the well intentioned justification of every other poster who has also routed the lines as you have.
the rationalization "this is how I've always done it and never had a problem" or "this how lots of other people have done it" is anecdotal and thus not germane when determining best practices. A poster intends to be helpful by passing along personal experience, but this intention doesn't validate the conclusion, i.e. "this is the correct way."
nely is correct: "Otherwise it will just flow in the top, thru a few of the cooler fins and go out the bottom."
as is the great him: "if your inlet line is at the top and the return is at the bottom the cooler will never fill up and will be ineffective."
as is Mcgyver1: "I read on either TruCool or B&M's website that it was the preferred method as it would eliminate air bubbles."

Transmission Cooler
http://www.toyota-4runner.org/3rd-gen-t4rs/139508-b-m-transmission-cooler.html
Transmission coolers - low temps and bypass thermostats - Tests and results - YotaTech Forums
http://www.toyota-4runner.org/3rd-gen-t4rs/138673-my-tranny-cooler-big-enough.html
and, of course, the write up of all wrote ups:
http://www.toyota-4runner.org/3rd-g...oler-transmission-cooler-install-3rd-gen.html.
You need to go up at least one size when bypassing the stock cooler because you are losing that cooling capacity.
you can Google the crap out of this via "3rd gen 4runner whatever-phrasing/search terms-you-want"
This is all I have to contribute to your query.
 
the great him said:
Oh boy here we go again... Raising Lazarus the horse from the dead only to beat him again...
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I never read that "thread" until an hour ago, so now I know what you mean lol. But could I get your opinion? Would having the send line(from tranny to cooler) at the top and the return at the bottom be a bad thing? Is it really necessary for me to change or it works fine either way?
 
Amirocassar said:
I never read that "thread" until an hour ago, so now I know what you mean lol. But could I get your opinion? Would having the send line(from tranny to cooler) at the top and the return at the bottom be a bad thing? Is it really necessary for me to change or it works fine either way?
Click to expand...

From the info already presented, especially in Slapdappy's last post, you should be able to form your own opinion.
 
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