Brake Tube Repair

Only double wall 4.75mm (3/16 inch) steel tubing with the correct tube nuts are to be used for replacement of a hydraulic brake tube.
Care should be taken when repairing 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.

Cutting And Flaring Of Brake Tubing:

Brake Fluid Tube Preparation For Flaring:

Using Tubing Cutter, Special Tool C-3478-A or an equivalent, cut off the damaged seat or 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. PLACE TUBE NUT ON TUBING BEFORE FLARING THE TUBING.

Double Inverted Tubing Flares

Double Inverted Brake Line Tubing Flare:

Double Wall Inverted Flare Connection:

To make a double inverted tubing flare. Open handles of Flaring Tool, Special Tool C-4047 or equivalent. Then rotate jaws of tool until the mating jaws of tubing size are centered between vertical posts on tool. Slowly close handles with tubing inserted in jaws but do not apply heavy pressure to handle as this will lock tubing in place.
Place gauge (Form A) on edge over end of brake tubing. Push tubing through jaws until end of tubing contacts the recessed notch in gauge matching the tubing size. Squeeze handles of flaring tool and lock tubing in place. Place 3/16 inch plug of gauge (A) down in end of tubing. Swing compression disc over gauge and center tapered flaring screw in recess of disc. Screw in until plug gauge has seated on jaws of flaring tool. This action has started to invert the extended end of the tubing. Remove gauge and continue to screw down until tool is firmly seated in tubing. Remove tubing from flaring tool and inspect seat. Refer to tube routing diagrams found under Description and Operation, General Information for proper brake tube routing and clip locations. Replace any damaged tube routing clips.

ISO Tubing Flares

ISO Style Tubing Flare And Nut:

ISO Tubing Flare Connection:

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

ISO Tubing Flare Process:

To create a (metric) ISO style tubing flare, Use Snap On Flaring Tool TFM 428, or equivalent. See illustration and proceed with the steps listed below. Be sure to place the tubing nut on the tube before flaring the tubing.

Brake Fluid Tube Preparation For Flaring:

1. Carefully prepare the end of the tubing to be flared. Be sure the end of the tubing to be flared 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 mating size jaws of the flaring tool around the size of the tubing to be flared. Close the jaws of the Flaring
Tool around the tubing to keep it from sliding out of the flaring tool, but do not lock the tubing in place.
3. Position the tubing in the jaws of the Flaring Tool so that it is flush with the top surface of the flaring tool bar assembly.
4. Install the correct size adapter 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 brake tubing. Making sure the adapter pilot is fully inserted in the end of the brake tubing. Screw in the feed screw of the yoke assembly until the adapter has seated squarely on the surface of the bar assembly. This process has created the (metric) ISO tubing flare.