2001-2016 Duramax S300 or S400 Return Drain Line Kit - JCG

You are looking at a turbo return line kit from John C Garage that fits 2001-2016 Duramax trucks running an S300 or S400 turbo! We have found that the AN style lines in some of the S300/S400 kits are too restrictive causing oil to push out of the seals on the turbo. Using this line, it opens the diameter to 7/8" which is larger than -12 being 3/4" and -10 which is supposed to be 5/8" but usually shrunk down even more! You will need to ultilize the factory VGT return line with this kit as shown in pictures. You make a cut right at the bellow and discard the top portion of the factory line. You will install the provided billet turbo adapter with integrated oring seal onto the bottom of your S300/S400 turbo, then run the oil/fuel rated hose provided in the kit down to the factory drain line. Using the two provided non perforated clamps, you can secure that hose to each end and you have the largest drain possible for your fixed geometry turbo! We use this kit on pedestals with 5.5" tall pedestal. If you have a taller pedestal, we may need to provide a slightly longer line so just let us know ahead of time.