TH400 Trans Cooler Line Location

[JustLiveIt]

I have searched for the last half hour and can not find the thread that talks about which cooler line goes to the top fitting and which one to the bottom fitting on the turbo 400.

So can anybody provide the link or tell me if its top of rad to top fitting and bottom of rad to bottom fitting?

Thanks, Mike

[crazy longhorn]

The lower fitting on thje trans is pressure out, & goes to the lower fitting on the radiator. The cooler feeds from the bottom to the top to eliminate air bubbles...... L

[JustLiveIt]

Thank you very much!

I know I saw the answer to my question a few months back but could not find the thread.

Mike

[VetteVet]

Here's a diagram I saved that shows how they go.

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[JustLiveIt]

Thanks so much!

I got the lines on and the higher pressure "hot" line leaks. Any suggestions or should I just get her as tight as I can?

I have gotten so much info from this board that I could not put off becoming a site supporter anymore!

[mrein3]

No offense but that picture is a bit misleading IF YOU LIVE IN A COLD CLIMATE AND DRIVE YOUR TRUCK IN THE WINTER. (I know the orginal post was from somebody in Cali but others read these posts).

You southern guys want your hot fluid going to the radiator FIRST, then the auxiliary cooler, then back to the tranny.

Up north in the winter you want to send your fluid first to the auxiliary cooler then from their to the radiator to HEAT the tranny fluid.

Too cold can be just as bad as too hot.

One overly anal guy I know up here re-plumbs his winter to summer. He also waits until his tranny temp gauge reaches 100F before he takes off.

[VetteVet]

Originally Posted by mrein3

No offense but that picture is a bit misleading IF YOU LIVE IN A COLD CLIMATE AND DRIVE YOUR TRUCK IN THE WINTER. (I know the orginal post was from somebody in Cali but others read these posts).

You southern guys want your hot fluid going to the radiator FIRST, then the auxiliary cooler, then back to the tranny.

Up north in the winter you want to send your fluid first to the auxiliary cooler then from their to the radiator to HEAT the tranny fluid.

Too cold can be just as bad as too hot.

One overly anal guy I know up here re-plumbs his winter to summer. He also waits until his tranny temp gauge reaches 100F before he takes off.

That's an interesting concept. The only problem is that liquid to liquid transfers heat a lot faster than air to liquid. Therefore if you wanted to heat or cool the trans fluid faster you have to send it to the radiator first.
My contention is that the trans fluid is going to heat faster and get hotter than the coolant anyway due to the torque converter slippage and the pressure generated by the front pump.
The picture I posted shows how the lines are routed with a cooler in the circuit and the op did not ask for that. Most guys run one so it is pertinent. The original chevy gmc trucks did not come with a cooler anyway and they used them up north without any issues.
Anyone who reads any post in these forums must draw their own conclusions about whether the information they read is factual or flawed. That's my disclaimer, LOL.