GM 4L80E leaking transmission cooler lines.

Your welcome. I purchased the Tru-Cool 40k from Oregon Performance Transmission, they have a nice website. Just purchase an extra 4' piece of the same transmission cooler line, LNG-723, if/when you order the cooler.
Good luck.

Thanks Geoboy! The oem crimp connecters are the problem.

I added a Tru-Cool 40K and just ran rubber transmission rated hose from the radiator to the cooler and then rubber transmission hose from the cooler to the return line going back to the transmission. I took a die grinder with a cut off wheel and cut the metal crimp on the factory lines, where the rubber hoses are and you will find a ferrel that you can just put the rubber line, with clamps, on to and from the cooler.

will do. I was considering adding an additional cooler, but will have to deal with OEM leakers too.

PAThwacker wrote:
The factory trans cooler hose connecters are failing on my 2004 K2500 sub. Are there aftermarket coolers or approaches to eliminating/disabling the factory cooler?

Do yourself a favor and just get new hoses for the factory cooler. If you want to get really fancy you can have a hydraulic shop make some up for you that will never fail.