Hydraulic Flaring Tool Kit, GM Transmission Cooler Line 32pc

This is a bench and truck-box flaring kit built around a hydraulic ram instead of a screw clamp, so the die does the work and the flare comes out square every time. It covers the seven flare types you actually run into under a vehicle: 45 degree single and double, ISO/DIN bubble, push-connect, GM fuel line, GM transmission cooler line, and plain hydraulic. Tube sizes are 3/16, 1/4, 5/16, 3/8 and 1/2 inch, plus 4.75mm, 6mm, 8mm and 10mm metric.

The reason it matters on a transmission job: GM cooler lines use their own flare profile, and a standard 45 degree double flare die will not seal against that fitting. Splice a rusted 4L60E or 4L80E cooler line with the wrong flare and you get a slow weep at the radiator end that shows up as a low-fluid burn a month later. This kit has the correct GM transmission cooler die in it, so you can cut the rotten section out, deburr, and re-flare in place rather than chasing a whole new line assembly.

On the bench the sequence is short. Cut the tube with the included mini cutter, deburr both ends, slide the fitting on before you flare (the mistake everyone makes once), clamp the tube in the labeled die, seat the stabilizing arm, and pump the ram until it stops. The auto-return spring pulls the ram back on its own and the pressure relief valve keeps you from over-forming the flare. Dies are stamped with their size so you are not holding two of them up to the light guessing.

32 pieces total in a blow-molded case with cut-outs, including the ram, die sets, tube cutter, deburring tool and the stabilizing arm. Manufacturer part number MU-CT-410. Shipping weight is about 14 pounds.