Brake Tube Flaring

OVERVIEW






All available brake systems on this vehicle use ISO STYLE TUBING FLARES at all chassis brake tube to component locations, Only the connection between the rear proportioning valve and flex hose uses a double inverted flare.
Only double wall 4.75mm (3/16 inch) steel tubing should be used for replacement of the chassis brake tubes. The chassis brake tubes used on this vehicle are coated with a zinc alloy and aluminum rich coating referred to as Prokote 2000. If a chassis brake tube requires replacement, only brake tubing with the same coating should be used as a service replacement. Care should be taken when replacing brake tubing, to be sure the proper bending and flaring tools and procedures are used, to avoid kinking. Do not route the tubes against sharp edges, moving components or into hot areas. All tubes should be properly attached with recommended retaining clips and fasteners.
Care must be taken when servicing components to avoid damage to the flexible stainless steel hoses between the master cylinder and junction block or antilock hydraulic control unit.

ISO STYLE TUBE FLARING PROCEDURE

CAUTION: ALWAYS USE THE PROPER TYPE OF ISO FLARING TOOL AND REQUIRED PROCEDURE, WHEN TUBE FLARING IS REQUIRED WHEN SERVICING THE VEHICLES HYDRAULIC BRAKE SYSTEM. THIS IS REQUIRED TO ENSURE THE INTEGRITY OF THE VEHICLE'S HYDRAULIC BRAKING SYSTEM.

Cutting And Flaring Of Brake Line Tubing:

Tube End Properly Prepared For Flaring:

Using Tubing Cutter, Special Tool C-3478-A or equivalent, cut off damaged seat on tubing. Ream out any burrs or rough edges showing on inside of tubing. This will make the ends of tubing square and ensure better seating of flared end tubing. Be sure to put the tube nut on tubing before the tubing is flared.

CAUTION: All ISO style tubing flares are of metric dimensions. When performing any service procedures on a vehicle using ISO style tubing flares, metric size tubing of 4.75 mm MUST be used with metric ISO tube flaring equipment.






To create a (metric) ISO style tubing flare, use Snap-On Flaring Tool TFM-428, or the equivalent. See figure and proceed with the steps listed below. Be sure to place the tubing nut on tube before proceeding to flare the tubing.
1. Carefully prepare the end of the tubing to be flared. Be sure the end of the tubing is square and all burrs on the inside of the tubing are removed. This preparation is essential to obtain the correct form of a (metric) ISO tubing flare.
2. Open the jaws of the Flaring Tool. Align the jaws of the flaring tool around the tubing. Close the jaws of the Flaring Tool around the tubing, but do not lock the tubing in place.
3. Position tubing in jaws of the Flaring Tool so that it is flush with top surface of flaring tool bar assembly.
4. Install the correct size adaptor for the brake tubing being flared, on the feed screw of the yoke assembly. Center the yoke and adapter over the end of the tubing. Apply lubricant to the adapter area that contacts the brake tubing. Make sure the adapter pilot is fully inserted in the end of the brake tubing. Tighten screw on yoke assembly until the adaptor has seated squarely on the surface of the bar assembly. This process will properly create a metric ISO tubing flare.