GM Service Manual Online
For 1990-2009 cars only

Tools Required

J 29803-A ISO Flaring Kit

Caution: Always use double walled steel brake pipe when replacing brake pipes. The use of any other pipe is not recommended and may cause brake system failure. Carefully route and retain replacement brake pipes. Always use the correct fasteners and the original location for replacement brake pipes. Failure to properly route and retain brake pipes may cause damage to the brake pipes and cause brake system failure.


    Object Number: 63933  Size: SH
  1. Obtain the correct size pipe and the correct size steel fitting nuts.
  2. Use the outside diameter of the pipe in order to specify the size.

  3. Cut the pipe square and to the correct length using a hack saw.
  4. Measure the old pipe in order to determine the correct length of the pipe. Use a string in order to measure, and add 3.2 mm (0.125 in) for each ISO flare.
  5. Install the fittings before starting the flare.
  6. Chamfer the inside and the outside diameter of the pipe using a de-burring tool.
  7. Remove all traces of lubricant from the brake pipe and the J 29803-A .

  8. Object Number: 63931  Size: SH
  9. Clamp the J 29803-A in a vise.
  10. Select the correct size collet (2) and forming mandrel for the pipe size used.

  11. Object Number: 63927  Size: SH
  12. Insert the properly formed mandrel (3) into the J 29803-A .
  13. Hold the forming mandrel (3) in place using your finger.
  14. Thread in the forcing screw (2) until contact is made and the screw begins to move the forming mandrel (3).

  15. Object Number: 63931  Size: SH
  16. Turn the forcing screw back one complete turn.
  17. Slide the clamping nut over the brake pipe.
  18. Insert the prepared brake pipe into the correct collet (2).
  19. Leave approximately 19 mm (0.750 in) of tubing extending out of the collet.

    Insert the assembly into the J 29803-A .

    Ensure that the brake pipe end contacts the face of the forming mandrel.

  20. Tighten the clamping nut (1) into the J 29803-A body tightly in order to ensure that the pipe will not push out.
  21. Wrench tighten the forcing screw until the screw bottoms. Do not over tighten the forcing screw or the flare may become oversized.
  22. Back the clamping nut (1) out of the J 29803-A .
  23. Disassemble the clamping nut (1) and the collet assembly.
  24. Measure the flare diameter. It should fall between 6.92 mm and 7.28 mm (0.272 in and 0.286 in).
  25. The flare is now ready for use.

  26. Object Number: 219471  Size: SH
  27. Use a tube bender in order to bend the new pipe to match the old pipe.
  28. Maintain the following clearances:
  29. • Maintain the minimum clearance of 19 mm (0.75 in) to all moving components.
    • Maintain the minimum clearance of 13 mm (0.50 in) to all vibrating components.
    • Maintain the minimum clearance of 7 mm (0.25 in) to any shielded lines, unless clipped to a component.