tranny cooler lines... confused

[mo]

I am having a hard time understanding what is going on with my tranny cooler lines. I am running two coolers now with a fan and briefly with a remote filter. Yet my tranny temp will still climb right up to 250 if i let it, in my driveway doing nothing.

here's a crappy diagram of my setup...

I was thinking maybe the filter was being too restrictive, and not allowing enough ciculation so I unhooked the lines at joint #2 and tested to see if much fluid would come out of the cooler filter setup. I was surprised when a hole bunch of fluid came out the return line off the tranny (side B) and very little came out side A.

So i thought maybe i had the lines reversed and that line wasn't the return line, so i swapped the lines. same thing happened, lotsa fluid out the tranny side, not much through the cooler setup.

So does fluid come out the return line if there is a restriction in the out line (such as an inline filter)?

So i took the filter out of the loop, but still did not return fluid into the tranny (Joint 2 unhooked). this time more fluid ran through the coolers and out side A, but a good amount still came out of the return line on the tranny (side B), which doesn't make any sense to me.

Maybe if there is no pressure pushing in on the return line, then fluid will come out of it also?

thanks!

 

[dsmd58]

have you checked your sender? 250 and not even moving is weird...,

 

[ryoken]

http://www.tciauto.com/Products/TechInfo/cooler_fittings.asp

 

[badmix]

Id say changing sending unit and gauge. I run 175degrees while off roading and 150degrees normal driving. And it takes awhile to get up to temps from a cold idle.

 

[hmatiak]

I would try taking the radiator cooler out of the mix. You have allot of extra line for the trans to pump that fluid through. What kind of after market coolers do you have? Is it a plate style, or the tube and fin? Remember also that after adding all the extra line you need to add fluid and check it often to make sure its back up to full. If you are low, then it can heat things up quick. Also the top line on the radiator is coming from the trans (being pumped), and the bottom is the return, which should be your cooler fluid after passing through everything else. Honestly IMO, i would stick with a single plate style cooler. Just get the biggest GVW rating one you can find.

 

[hmatiak]

To make sure im clear, if you do take the radiator cooler out there are some drawbacks. The factory setup is that way for two reasons. One to heat the cold fluid so the trans will perform optimally and also to cool it when it becomes over the ideal temp. The best why IMO to run the coolers is to have it after the stock setup, and before the return back to the trans. This is the way i have it one my DD, and this is the way i will do it on my latest build. Also a small stand alone fan isnt a bad idea to keep the trail temp down.

I only recomended bypassing the stocker previously to test if there could have been some sort of blockage. Make sure your line are correct and fluid levels too before getting to creative.

 

[JDNobodi]

I think how you plumb your cooler could have an effect. I think if your cooler has the fittings top and bottom, you would plumb in bottom as the inlet. I don't know what the joint is in your diagrams, but I have basically the set as yours. I however, have the filter plumbed in last.

 

[mo]

thanks guys for the help, I have the lines coming off the tranny correct per the link abbove which is how I thought it was suppossed to be. I just tried swapping them to be sure, but still got fluid coming out of the return (into tranny) line for some reason.

I am not running it through the radiator cooler at all. I have one B&M stack plate cooler, and one tube/fin cooler with a small electric fan. I keprt the fluid level up since I was pumping a bunch out when I unhooked the joints. the joints are just where i am running the rubber tranny hose off the metal tubes that to the tranny.

I let the tranny cool down to where the guage was at around 150 or so, and felt some of the fluid coming out when i had disconnected things and it was pretty hot. didn't burn myself, but definitely hotter than faucet water...

I will double check everything again, but does anyone know if fluid will come out of the return line if there is no pressure pushing fluid back into the tranny?

 

[hmatiak]

If you are getting pumping fluid out of both lines, i'd say that its the trans, not your cooler setup. Its a simple mapping, you should NOT be getting pressurized fluid form both ends. Also the fluid is going to heat up under the pressure of passing through the external filter.

-Heath

 

[Mike D]

One thing to remember ATF is an oil and does not easily exchange heat. That's why you don't fill the radiator with transmisson fluid. Water is the best heat transfer fluid.
If you use a 24,000 BTU transmisson cooler, by pass the extra filter, and use AN6 ( 3/8" ) steel braded hose you will minimize flow restrictions to maximize heat exchange.
I was informed by a transmisson shop that the fluid lines are from the torque converter and return the cooled fluid to the pan. Most of the heat generated is from the torque converter when it is doing its thing, multiplying torque - slipping, fluid from the rest of the hydraulics are not sent to the cooler.
I don't know if all automatic transmissons are set up the same way or just rear wheel drive trannys.