REMOVAL & INSTALLATION
The hydraulic brake lines and brake linings are to be inspected at the recommended intervals in the maintenance schedule. Follow the steel tubing from the master cylinder to the flexible hose fitting at each wheel. If a section of the tubing is found to be damaged, replace the entire section with tubing of the same type (steel, not copper), size, shape, and length. When installing a new section of brake tubing, flush clean brake fluid or denatured alcohol through to remove any dirt or foreign material from the line. Be sure to flare both ends to provide sound, leak-proof connections. When bending the tubing to fit the underbody contours, be careful not to kink or crack the line. Torque all hydraulic connections to 10-15 ft. lbs. (13.5-20 Nm).Flexible Hoses
Check the flexible brake hoses that connect the steel tubing to each wheel cylinder. Replace a hose if it shows any signs of softening, cracking, or other damage. When installing a new front brake hose, position the hose to avoid contact with other chassis parts. Place a new copper gasket over the hose fitting and thread the hose assembly into the front wheel cylinder. A new rear brake hose must be positioned clear of the exhaust pipe or shock absorber. Thread the hose into the rear brake tube connector. When installing either a new front or rear brake hose, engage the opposite end of the hose to the bracket on the frame. Install the horseshoe type retaining clip and connect the tube to the hose with the tube fitting nut.
Always bleed the system after hose or line replacement. Before bleeding, make sure that the master cylinder is topped up with high temperature, extra heavy duty fluid of at least SAE 70R3 quality.Steel Pipes
See Figure 1
When replacing steel brake pipes, always use the double-walled steel piping which is designed to withstand high pressure and resist corrosion. Also, it is important to make sure that the pipe is of the same size to assure both a proper fit and proper brake operation.
Whenever possible, try to work with brake lines that are already cut to the length needed. These lines are available at most auto parts stores and have machine made flares, the quality of which is hard to duplicate with most of the available inexpensive flaring kits.
When the brakes are applied, there is a great deal of pressure developed in the hydraulic system. An improperly formed flare can leak with a resultant loss of stopping power. If you have never formed a double-flare, take time to familiarize yourself with the flaring kit; practice forming double-flares on scrap tubing until you are satisfied with the results.
- Obtain the recommended bulk 3 / 16 in. double wall steel brake tubing and the correct standard tube nuts for 3 / 16 in. tubing.
The outside diameter of the line is used to specify size.
- Using a tubing cutter, cut the tubing to the proper length. Clean burrs after cutting. The correct length may be determined by measuring the line to be replaced using a length of cord, then adding 1 / 8 in. (1.2mm) for each flare.
Make sure the fittings are installed and oriented correctly before flaring both ends of the line.
- Place a tube nut onto the tube in the correct direction, then flare the tube with an SAE inverted flare or a metric ISO flare using Brake Line Flaring Tool D81L-2269-A, or equivalent. Carefully follow the instructions included with the tool. Repeat on the opposite end of the tube.
- Bend the replacement tube to match the removed tube using a tubing bender. When the replacement brake tube is installed, maintain adequate clearance to metal edges and moving or vibrating parts.
- Clean the brake tube by flushing with clean brake fluid. Install the brake tube, then tighten the tube nuts to specification using an inch lb. torque wrench.
- Bleed the brake system.