Tranny Cooler Leak Issue

[mchestnut]

hi all -

I know tranny cooler install is covered in depth on the forum, and was very helpful during the install process.

Using these links I installed the suggested Hayden Automotive 512 High Performance Transmission Cooler: https://www.amazon.com/gp/product/B000C3DDEA/ref=oh_aui_search_detailpage?ie=UTF8&psc=1


I installed the transmission in line with the radiator, and it was a pretty smooth and seamless process. However I'm running into an unexpected issue post install (here about 10 months post-install) which is that I get a slow drip leak (4-5 drip puddle/night) that originates at the metal connections where the transmission fluid enters/exits the unit (see picture).

Makes me think that the unit needs a rubber gasket at that connection point, but none was included. Instead it is a metal on metal connection.

To address this I tightened these down as much as possible by hand, which stopped the drip for about one week.

The drip is now back, and I'm not sure what to do next.

 

[AuSeeker]

There's nothing you can do but tighten connection further, the connection is a "flare" fitting, in that the
metal tubing on the cooler is flared out and fits the taper on the threaded fitting that connects to the rubber hose,
this is the same connection that is used on hydraulic brake lines and plumbing water connections,
to tighten them properly without rounding off the hex fitting/nut you really need to use "Flare nut wrenches"
which are similar to a box end wrench but with a slot cut only big enough to get over the hydraulic line and
then onto the hex of the fitting/nut, if you try and tighten it any further with open-end wrenches you risk the wrench slipping and
rounding off the hex fitting/nut.

Husky SAE & MM Flare Nut Wrench Set (6-Piece)-HFNW6PC - The Home Depot

 

[mchestnut]

Thanks [MENTION=149207]AuSeeker[/MENTION] -

Sounds like this issue is not uncommon? The unit has a 5 year warranty and I was considering returning, would that be worthwhile or not so much? Sounds like not so much.

I'm tempted to just cut the cooler out of the in line setup and forget about the whole idea so that I no longer have to monitor for drips.

Lastly - this has been going on for 2-3 months. I'm now worried that the loss of tranny fluid requires at least a top off if not a flush/reload. Problem is that there is no easy way to tell as the reservoir does not have a dipstick. Would appreciate your thoughts there as well.

 

[Caltech90]

Those look like AN fittings, they should not have any tape/gasket on the sealing surface. If tightening them doesn't work they might be scored on the sealing surface.

 

[AuSeeker]

Thanks [MENTION=149207]AuSeeker[/MENTION] -

Sounds like this issue is not uncommon? The unit has a 5 year warranty and I was considering returning, would that be worthwhile or not so much? Sounds like not so much.

I'm tempted to just cut the cooler out of the in line setup and forget about the whole idea so that I no longer have to monitor for drips.

Lastly - this has been going on for 2-3 months. I'm now worried that the loss of tranny fluid requires at least a top off if not a flush/reload. Problem is that there is no easy way to tell as the reservoir does not have a dipstick. Would appreciate your thoughts there as well.

A flare fitting can have 2 reasons for leaking, not tight enough or having been over tighten which can especially with copper or brass deform or spit the tubing, with these fittings it's best to at first just tighten them snuggly and then check for leaks and if necessary tighten a bit more, as I mentioned these same fittings are used for brake lines and as such they wouldn't be use in such a critical application if it was common for them to leak, but usually are made entirely of steel and leaking is not usally an issue when correctly tightened, if the tubing is copper or brass it's more critical to not over tighten them, not sure what the tubing on your cooler is, if it's steel I would definitely try to tighten the fittings again which the proper tools, the risk of deforming is greatly reduce if steel.

Since there's no dipstick and if you aren't capable of checking the fluid level via the plug on the pan with the fluid up to the proper temperature, which definitely needs to be done, take it in and have a professional do so, if your fluid hasn't been changed in some time it would be the time to do so, but getting the leak fix needs to be done first ASAP!!