Metal pipes are especially prone to damage and bending under the vehicle. Any such deformation can restrict normal fluid flow and therefore reduce brake action. Rubber hoses should be checked for cracks or scratches; such damage can damage the hose under pressure.
When removing or disconnecting pipelines, extreme cleanliness must always be observed. A small piece of dirt in the system can clog the channel, resulting in brake failure. Clean all connections before disassembly (use a stiff brush and clean brake fluid) and plug all pipes and channels as soon as they open. New piping and hoses must be purged or flushed thoroughly before installation to eliminate any contamination.
Removal and installation
1. Raise and secure the vehicle.
2. Remove the wheel (wheels) as needed.
3. Clean the area around the connections that will be disconnected.
4. Place a pallet under the joints to be separated.
5. Disconnect the required piping and hoses using two wrenches - one to hold the connection and one to rotate.
6. Disconnect the other end of the tubing or hose by moving the drain pan if necessary. Always use two wrenches whenever possible.
7. Disconnect any fastening clips or collars holding the pipeline, and remove the pipeline.
8. If the system must remain open for longer than required to re-pipe, wrap or plug remaining piping and passages to prevent dirt and fluid from entering from the outside.
9. Install the new piping or hose, starting at the end farthest from the master cylinder. Connect the other end and check that both joints are properly baited. Tighten gently with your fingers. Make sure the new piping won't rub against other parts. The brake lines must be at least 13 mm away from the steering column and other moving parts. All guards or insulators must be reinstalled in their original position.
If you need to bend a new metal pipe, do it carefully using a pipe bender. Do not attempt to bend by hand; you can inadvertently bend and ruin the pipeline.
10. Using two wrenches, tighten each fitting 13-17 Nm. The brake hoses connected to the front or rear calipers must be tightened to 35 Nm. Pipelines connecting to the rear wheel cylinders (drum brakes), must be tightened to 19 Nm.
11. Install any mounting clips or clamps on the piping.
12. Fill reservoir with clean, fresh brake fluid.
13. Bleed the brake system.
14. Install the wheels and lower the vehicle to the ground.