Transmission cooler lines are cold

[DavidL]

So, I replaced the radiator on my 99 Taurus as I mentioned in another thread. Today I decided to look it over while the engine was hot to look for any leaks. I grabbed each transmission cooler line to see how hot they are getting and, surprise, they weren't hot at all (other than within a couple inches of the transmission from conduction through the metal line). It looks to me like I am getting no flow to the transmission cooler section of the radiator. Could there be come kind of vapor lock going on? I guess the obvious thing to do would be to pull one of the lines out of the cooler and look for flow, but we had a heck of a time getting those lines all the way in the first time. Any ideas on what would be preventing flow and how to fix it?

[thisnametooktolong]

Because those lines are the return for the entire transmission, and the pump is sucking fluid off of the bottom of the pan then going through all of the "stuff". There is no way that those lines can have vapor lock.tranny fluid will run very hot and is not lick gas at all. Now, I know for a fact that if there is no flow through those lines the tranny will not work so that is not a factor. I am concerned though. The reason why I am concerned is because the factory cooler not only cools the transmission fluid but it also heats it. there is no way that the fluid can go through a "cooler" that is running at 194F and not pick up some heat on the way. I cannot fathom how on earth those lines could possibly be cool and the car is also moving? Personally I would check the routing and make sure that I did not step on any of my reproductive organs when I installed the radiator. I can’t think of how you may have done it, but did you some how bypass the cooler? In any event if after a drive of like 10 miles and those lines are not fairly hot you have a problem and you are cooking the tranny. As long as you are at it and we all know that those oxd ax4n and ax4s trannys are fragile.... grab yourself a cooler off a ford truck and add it to the system. In series. My old sable has 2005K miles on it with the original tranny that I tow with all the time. My boat weighs 4000lbs and I dolly cars with it all the time. The factory guys traded Heat for gas mileage in those cars and that was a bad idea. The heat cooks a relatively tough transmission, turning it to one of the worst trannys of all time. In reality it ranks up there with the C-6, and the GM Th400. I believe if properly cooled it is almost as good as the Turbo glide and a lot better than the FMX.


(Congratulations on the radiator they are a pain on those cars. last year I had a woman that caught rebar through the A/C and radiator. I stuck a piece of rebar back through the thing cracked 6 eggs in her radiator and told her to check every shop on the planet first, I charged 575$ to fix everything (a/c and radiator) She was so Happy it was not funny. She actually gave me a 100$ tip (that was with new parts, and her A/C had not worked in years))

[DavidL]

I checked it again this evening and this time the lines were hot. The only thing I can think of is that the car had sat long enough for those skinny lines to cool off, even though the engine was still pretty warm. My son drives the car, so I'm not sure how long it had been sitting when I checked it. The inlet radiator hose was still pretty hot, so I thought the other lines should be, also.

As far as the radiator is concerned, I have to give my son credit for that. He tore into it with help from a friend and they got the old one out. Then he did most of the installation of the new one by himself.