Transmission Coolant leak between transmission and intercooler

[PStone]

2001Ram 2500 4WD 201,000 miles

Hello Folks,

I just had a total transmission rebuild July 2019. Truck was downshifting/upshifting at 50 MPH. Last week I noticed a puddle of transmission fluid on the floor in my garage. Took it back to the transmission shop. They said it was down two quarts of fluid and was leaking at the unit mounted on the engine that heats the fluid up when you first start it. What is that called and where can I get one? The transmission shop guys said they saw this problem once before and couldn't locate one anywhere. Any help would be appreciated. Thank you

Pete Stone

 

[Ozymandias]

That's the water/oil heat exchanger, the main cooling device for the transmission on our trucks.

It is a little sissy if it comes to torque the oil lines to it, done wrong it breaks and therefore leaks afterwards.

And it is not cheap..
https://www.google.com/search?q=5014861AA&ie=utf-8&oe=utf-8&client=firefox-b-m

Part# 5014861AA

 

[Timd32]

If it's this cooler, I got one from here for my 96, was hard to find aftermarket fittings had to reuse my old ones.

Looks like they have the 98-02 as well.

Yeah dont go to cummins they are extreme pricing.


https://www.americancoolingsolution...-ram-cummins-transmission-oil-cooler-3935812/

 

[PStone]

Thank you both for your help. I love this truck but its starting to get expensive.

 

[Ozymandias]

Well i see the transmission shop as your warranty station, they messed it up while changing the transmission.

 

[Timd32]

Unless it looks like mine before they started. Mine was just a typical NE truck with years of salt damage. Then cant really blame them.

I basically redid the whole system with a mix of Cummins parts, Mr Bob's Hoses, New Brackets, Hardware, and trans fluid coolant. heater. Cummins wanted like $1,500 or more for that thing for my 96 anyway.
Yes agree these are still expensive to keep up on.

 

[Timd32]

Forgot to mention this could just the lines are loose? Mine leaked when I did it, had to snug up the fittings and the line connections.

Also if the unit is shot it could be bypassed with a small hose set up if needed. This is a "heater" of sorts not really a "cooler", while it really does both at times. Many have gotten rid of it.

I would bypass both the trans part and coolant part if it looked like mine. It's in a really bad spot on my 96.

 

[rotohead]

Unless you are living in Canada, AK or other super cold place you can delete the whole heat exchanger and not have to deal with it. FullSendDiesel.com offers a braided line kit to delete it bypassing so the transmission fluid goes straight to the cooler on the front of the truck, bypass the cabin heat fittings below the oil filter. It's somewhat pricey but they make a super quality product and will customize it for whatever you want. I did mine about a year ago and have had no issues since. I live near Lake Tahoe so get some cold winters here and no issues in the summer either. Very glad I did it and no more worrying about coolant getting in my transmission or vise versa.

 

[rotohead]

Unless you live in Canada, AK or other super cold location you can just delete the whole heat exchanger unit. FullSendDiesel.com sells a kit of braided lines that bypasses it and the transmission fluid goes straight to and from the cooler on the front of the truck. I think the nylon braided kit is probably a little cheaper then replacing the exchanger. I comes with lines that delete the fittings and other connections below the oil cooler and go straight to the heater core in the cabin. I live near Lake Tahoe and get some cold winters here and also driven and towed with it in the summer w/o any issues. No more worrying about coolant leaking into my transmission fluid or vise versa as the exchanger ages.

 

[rotohead]

I'll also add that deleting the heat exchanger and going with the straight braided lines will also remove the check ball in the flexible line that prevents drain back of the torque converter. The check ball can be problematic and stick not allowing fluid to get to the front cooler. Many people in the early years of the 2nd gens being sold would delete or drill out that check ball to insure the full flow of fluid. Two negatives to this 1) on first startup it takes a minute to allow the TC to fill (in over 20 years never been a problem) and 2) the dipstick will show over fill when the truck sits and cools completely down. To get a accurate measure of transmission fluid have to fully warm up and have it in neutral. Neither one of these 'negatives' have ever been issue for me in over 180,000 miles and half of that towing.

 

[Ozymandias]

Nice products they sell, thanks for posting this company.

 

[BigPapa]

I'll say, as I have before, that I have never known anyone PERSONALLY nor have I ever PERSONALLY seen a failed 2nd Gen Heat Exchanger mix fluids. I have seen some rusted out and some that leak but never one that mixed fluids. I have seen several 3rd Gens that have mixed fluids.

My father just bought a Chevy 1500 gasser in Florida and the radiator with built-in transmission cooler failed on the 10 hour drive home to TN, mixed the fluids, and toasted his transmission.

 

[Timd32]

Yeah mine was seeping externally, no issues internally mixing. All my hard lines were in the same shape really bad rusted out, really looked like they could fail. Hoses were all brittle.

NE trucks just get their butts kicked with salt and brine. Mine actually has a whole different frame due to rust.

I already had mine apart for other repairs so figured might as well just put it back to stock ot had made it that far with it.

But agree on the bypass would be fine.

 

[rotohead]

Of the 2 lines going from the trans up to that exchanger, the one that has the rubber section is the one that gets twisted and usually ends up leaking esp if it's more then 2 times it's been handled. There are replacement lines from Dorman that can be bought and some are the 1995 model year where there is a trans temp port right out of the transmission which I've found to be the most advantageous location to connect to a temp gauge. I could find that part # and post it if anyone is interested but it's buried in old computers so don't ask unless you speak nicely.

 

[rotohead]

I'll say, as I have before, that I have never known anyone PERSONALLY nor have I ever PERSONALLY seen a failed 2nd Gen Heat Exchanger mix fluids. I have seen some rusted out and some that leak but never one that mixed fluids. I have seen several 3rd Gens that have mixed fluids. ....

Since my second oil change almost 22 years ago and after my first trans rebuild 15 years ago I've used Blackstone Labs for oil analysis and they advised me they have seen incidence of coolant in the trans fluid. I've benefited from their expert advise before in spotting diesel in my oil from a leaking injector and it saved me big time. If they say it has happened was good enough for me. They see a lot more cases. Additionally, I'm one that if I need to replace a component I'd perfer to upgrade and make it better/simpler going forward. Also, Thoroughbreed Diesel on anything newer then the 2nd gens, when you add lets say the coolant bypass kit advises to delete the exchanger also. It's really a unnecessary item that was provided solely to address applications in extreme cold conditions. Considering the cost of a new exchanger, lines, etc and having mechanics wrench on that weak link of a fitting, verses any delete kit it's a no brainer to me. I'[m real happy I went the FullSendDiesel way. Kevin was a great guy to work with. I asked for a custom fitting for a temp probe and he did it for just a few dollars more.

 

[BigPapa]

Also, Thoroughbreed Diesel on anything newer then the 2nd gens, when you add lets say the coolant bypass kit advises to delete the exchanger also.

That’s what I said, no problem with the 2nd Gens mixing coolant. I’ve had the opportunity twice to remove mine but chose to keep it.

 

[rotohead]

That’s what I said, no problem with the 2nd Gens mixing coolant. I’ve had the opportunity twice to remove mine but chose to keep it.

TD advises to remove the heat exchanger because they feel it's overkill and not needed. Not because they leak and it interfers with the installation of a\their coolant bypass kit.