Transmission temps after bypass questions!

[Amirocassar]

So I did the bypass today with the b&m 70268. After about a 20minute drive I hit only 122F. Was actually a little nervous since it was so low(I'm a paranoid person). My real question is about the transmission lines. So I put mine sideways so that both ports are facing the passengers side with the send line st the top and the return at the bottom(obviously I did it because of gravity). I've seen others do it some weird ways or upside down which is apparently warned against by b&m. So my hoses were a PITA to get on to the transmission lines and I got them enough on that there was probably only a 1/8th gap between the hose and where it should be. I was struggling for hours and even used ATF to try to lube it on but it still was a pain. I used brand new screw clamps so does anybody think this could possibly be a problem in the future or I'm safe? I just couldn't get it on anymore and was so frustrated. I have work tonight(about a 10mile/20min drive ) so I just want to make sure this is acceptable before I f anything up.

Again I'm just a paranoid person so if anybody has some input it would help and be appreciated. If someone made a thread already asking this then I apologize.

 

[ajonesnv]

Run it and keep and eye out for leaks. I doubt you will loose much if you do leak at all and then you will know to fix it.

I would, if you did not, also wrap the lines that pass through any spot that has rubbing so that you don't end up rubbing a hole in the line.

 

[Amirocassar]

Run it and keep and eye out for leaks. I doubt you will loose much if you do leak at all and then you will know to fix it.

I would, if you did not, also wrap the lines that pass through any spot that has rubbing so that you don't end up rubbing a hole in the line.

Already did that I'll be watching the temps for the next few days. Thanks!

 

[Arnezie]

In from trans should be at bottom out back to trans should be on top, gravity has nothing to do with it.

 

[nely]

In from trans should be at bottom out back to trans should be on top, gravity has nothing to do with it.

What this guy said.

You want the fluid to go in thru the bottom, that way it forces the fluid up and causes all the fluid going thru to get cooled. Otherwise it will just flow in the top, thru a few of the cooler fins and go out the bottom.

The lines got switched at some point and this caused us to blow a few transmission on a race jeep I work on. You want it to feed from the bottom.

 

[Limbwalker]

What this guy said.

You want the fluid to go in thru the bottom, that way it forces the fluid up and causes all the fluid going thru to get cooled. Otherwise it will just flow in the top, thru a few of the cooler fins and go out the bottom.

The lines got switched at some point and this caused us to blow a few transmission on a race jeep I work on. You want it to feed from the bottom.

F. pretty sure i fed mine thru the top and return on bottom. Mines in series tho. Didnt see anything on install instructions that specified that it mattered

 

[the great him]

switch your lines, 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. not only that but you stated you drove it for 20min... you didnt say how or where or what the outside temp was. go drive it around town in stop and go traffic or on some hills at lower speed. out on the fwy will keep things cool. i run dual coolers and my temps can be around 130-150 on the fwy but can raise to 180 in town easily...

 

[Mgyver1]

Yes I would also recommend supply on the bottom and return on top, I read on either TruCool or B&M's website that it was the preferred method as it would eliminate airbubbles.

Also what size hose were you using? 3/8 line should slip on super easy. If you were using what came with the cooler kit, which is 11/32, then yes it'll be a pain to get on. They give you that stuff because in theory it will work with 3/8 or 5/16, but it is a pain to push on to the hard lines off the transmission.

 

[Limbwalker]

Guess Ill be switching mine today. My return is on bottom as well. Oh well, easy enough... Glad I saw this, thanks fellas

 

[Mgyver1]

Guess Ill be switching mine today. My return is on bottom as well. Oh well, easy enough... Glad I saw this, thanks fellas

I have tried finding the page where I read that info so I could source my claims, but so far I haven't been able to find it. I'm wondering if TruCool took it off their site or something but I will continue my search.

 

[kball]

I've had my inlet at the top and return to trans at the bottom since I installed it. My temp numbers are the same as everyone else's. Just sayin...

 

[slapdappy]

I put mine sideways so that both ports are facing the passengers side with the send line st the top and the return at the bottom(obviously I did it because of gravity).

wrong.
for sideways install inlet at bottom. outlet at top. this has been discussed to death. fluid from the transmission goes into lower fitting of the cooler. Cooled fluid comes out of the from upper fitting and returns to the transmission. In at the bottom, out at the top.

 

[19963.4lsr5]

And the factory Ford Explorer aux trans cooler I removed at the junkyard had the fittings pointing downward.

 

[LittleCaesar]

And the factory Ford Explorer aux trans cooler I removed at the junkyard had the fittings pointing downward.

A lot of good it must have done the Explorer if it is sitting in the junkyard, especially if it was the A4LD.

That said, I have always run my transmission cooler before then exchanger in the radiator, which one is not supposed to do. Not one problem with different vehicles in 20 years. If direction flown flow for the ATF was so important on a cooler, they would mark it on the cooler itself or put it somewhere in the directions IMHO.

 

[19963.4lsr5]

A lot of good it must have done the Explorer if it is sitting in the junkyard, especially if it was the A4LD.



That said, I have always run my transmission cooler before then exchanger in the radiator, which one is not supposed to do. Not one problem with different vehicles in 20 years. If direction flown flow for the ATF was so important on a cooler, they would mark it on the cooler itself or put it somewhere in the directions IMHO.

My factory aux cooler on my cummins is pre rad cooler. And the exploder had over 200,000 miles on it.

 

[Drcoffee]

In from trans should be at bottom out back to trans should be on top, gravity has nothing to do with it.

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.

 

[Amirocassar]

wrong.
for sideways install inlet at bottom. outlet at top. this has been discussed to death. fluid from the transmission goes into lower fitting of the cooler. Cooled fluid comes out of the from upper fitting and returns to the transmission. In at the bottom, out at the top.

Personally that doesn't make any sense. I need to look up these threads but that just doesn't sound right if you're following the rules of gravity. Doing it that way would make you always have to rely on pure pressure for the transmission oil to return.

 

[Amirocassar]

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.

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.

 

[KidVermicious]

In cold weather the trans fluid will gel or freeze in the trans cooler causing back pressure.

What temps are we talking about here? At what point does ATF start to gel?

Personally that doesn't make any sense. I need to look up these threads but that just doesn't sound right if you're following the rules of gravity. Doing it that way would make you always have to rely on pure pressure for the transmission oil to return.

I think you're not thinking this through. Gravity is a one way street. You're going to have to rely on pressure to complete the circuit no matter what.

 

[Amirocassar]

What temps are we talking about here? At what point does ATF start to gel?



I think you're not thinking this through. Gravity is a one way street. You're going to have to rely on pressure to complete the circuit no matter what.

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?