4L80E 6AN PTFE Transmission Cooler Line Kit, 70 Inch

A single 70 inch (5.8 ft) run of -6AN PTFE-lined hose with a stainless steel braid, sold as a kit with the end fittings shown. It is the setup most builders use to replace rusted hard lines or plumb an auxiliary cooler on a GM 4L80E, and it also fits the 700R4, 200-4R, TH350 and TH400, the Ford AOD, 4R70W and 4R100, and the TR6060. The fittings cover the common case port threads: 9/16-18 UNF, 3/8-18 NPT and 1/4-18 NPT.

On a 4L60E the case uses a 1/4 inch NPS quick-connect style port, so you need a separate -6AN to 1/4 NPS short adapter before this hose will thread in. Order that adapter with the kit if you are plumbing a 4L60E.

PTFE liner is the reason to pick this over rubber hose. It does not swell or break down in ATF, runs from -76F to 500F, and is rated for 3000 psi working pressure with a 10000 psi burst rating, so it holds up next to exhaust and in a hot tow rig. Measure the run from the case to the cooler or radiator tank before you cut. Cut the braid clean with a cutoff wheel or fine tooth blade, tape the end first so it does not fray, and seat the olive and socket fully before torquing the AN nut. Pressure test and check for weeps after the first heat cycle.