Trans fluid leaking from b&m cooler

[Illestreker]

I've had a b&m trans cooler for about a month now without any issues but recently drove a little over a thousand miles to Denver and just today noticed my lines are wet and the underside of the passenger side of the truck has a lot of trans fluid residue. I'm wondering if anyone has issues with leaks coming from any of the hose connections... I'm using the typical hose clamps but maybe their not tight enough even though I've tightened them as much as possible.

 

[Swimmerboy2112]

I've had a b&m trans cooler for about a month now without any issues but recently drove a little over a thousand miles to Denver and just today noticed my lines are wet and the underside of the passenger side of the truck has a lot of trans fluid residue. I'm wondering if anyone has issues with leaks coming from any of the hose connections... I'm using the typical hose clamps but maybe their not tight enough even though I've tightened them as much as possible.

Checked for a cracked hose. Also check to see if maybe the hose rubbed up against something and chaffed it causing the leak.

 

[amalik]

I'd recommend not driving until you figure this out... You are going to burn your tranny and be out $3-5k.

 

[the great him]

I'd recommend not driving until you figure this out... You are going to burn your tranny and be out $3-5k.

um or not....

he has not lost a lot from the sounds of things, he has wetness and residue, not a soaked undercarriage... and the trans will start slipping and givings signs when you get too low -not saying dont check the fluid, but he has had no signs of low fluid, and that would show long before actual damage has occurred.

to the OP, what kind of clamps are you using? try replacing those with typical hose clamps, have you checked your trans fluid level?

 

[LittleCaesar]

Get new hose clamps.

 

[Illestreker]

The hoses are pretty new so I cant see them dry or cracked at this point, unless some how there is a tear that oddly occurred during installation.

Rubbing and chaffing is highly unlikely because I do have all possible areas where this could occur protected with sleeves and it would take a very long time to rub through the hose causing a small hole/tare.

As for the clamps they are standard small hose clamps that come with the cooler or can be purchased at any auto store so I'm not sure how buying new ones would fix anything.

Tomorrow I'm going to clean everything and try and diagnos it further but at this point I'm just very confused why it would be leaking like this in the first place especially sense I just installed it a month ago and i was very meticulous doing it.

 

[kball]

Tighten the clamps more. I had this problem as well as others. Use a ratchet and 1/4" socket and crank it down.

 

[Illestreker]

After looking it more today it looks as if the leak was coming from the top hose connection to the cooler. I used some different clamps that are slightly wider and cranked them down pretty good. I also re routed the hoses a little to decrease the amount of sharp curves and bends. If it still leaks ill try new hoses.

 

[Illestreker]

I'm reviving this thread because I'm dealing with leaking trans fluid again due to the trans cooler and I'm looking for a better solution.

Last time I tightened down all the clamps and it stopped leaking for about 3-4 months but now its leaking AGAIN! This time you can see that where ever its leaking from its covering the radiator in oil. My radiator was brand new about 6 months ago and now its coated in black oily grime.

For how simple a trans cooler install is this has been a pain in the ass and I'm sick of dealing with leaks especially because I shouldn't have to worry about it leaking oil with this mod but even after tightening the hose clamps more last time the leaking it back and its very frustrating.

So ill ask again if any others deal with this and just keep tightening their hose clamps every couple months? Or is there a better solution that you be used like SS braided lines and AN fittings?

Seriously I wanna fix it and never wonder if its leaking ever again lol

 

[LittleCaesar]

Where did you get the trans hose from? What size did you buy?

I have seen people be sold PCV as well as vacuum hose for cooler installs from the folks behind the counter at the parts store.

 

[Drcoffee]

Go buy some new hose. If you used what came with the cooler, its too small and you are probably getting too much pressure at the inlet. They usually include 11/32 hose when you should be running 3/8". Also a big mistake is to use fuel line. Trans fluid eats fuel hose for lunch.

If you want to stop the leak, buy Gates transmission hose 3/8" ID and clamp with screw clamps.

 

[Illestreker]

Where did you get the trans hose from? What size did you buy?

I have seen people be sold PCV as well as vacuum hose for cooler installs from the folks behind the counter at the parts store.

originally I was sold cheap vacuum hose or heater hose whatever and it was "sweating" oil after realizing it was the wrong kind of hose I replaced it with the right kind. And yeah the size is 3/8.

 

[Illestreker]

Go buy some new hose. If you used what came with the cooler, its too small and you are probably getting too much pressure at the inlet. They usually include 11/32 hose when you should be running 3/8". Also a big mistake is to use fuel line. Trans fluid eats fuel hose for lunch.

If you want to stop the leak, buy Gates transmission hose 3/8" ID and clamp with screw clamps.

Great advice. I tightened up my clamps but only was able to get a couple turns more so we'll see how that works out but in the mean time I will look online for the gates trans hose.

 

[LittleCaesar]

Gates makes a good hose; if you can find it local Goodyear is tops in my book.

That said, if you are still leaking, try 11/32 hose. The diameter difference is .03125", but that might be the key to stopping the leak.