Attention: When processing the brake pipe, take care not to damage its polymer coating. Brake pipes are supplied mainly as goods sold by the meter. When manufacturing a brake pipe, it is necessary to pay attention to the thread diameter of the nipple. Put the corresponding nipple on the pipe and distribute the end of the pipe using a special device. Pay attention to the cutting of the end of the removed pipe. When bending the pipe, use the old pipe as a sample. To avoid kinks and pinches, use a special bending device.
Raise the car.
The brake pedal is easy to press and hold. To do this, place a board between the pedal and the seat as a spacer, moving the seat back and then forward accordingly. This prevents brake fluid from leaking out of the expansion tank and air from entering the system after disconnecting the brake line.
Loosen the union nuts and remove the brake line.
If necessary, plug the connection between the brake pipe and the master cylinder with a suitable plug.
If possible, lay the new brake pipe on the same surface. Tighten the threaded connection of the M12 pipe with a torque of 15 Nm, and M10 with a torque of 20 Nm.
Caution: Do not lay brake pipes between electrical wires. Otherwise, the brake system or electrical system may fail due to chafing. The distance between brake pipes and electrical wires should be no less than 25 mm.
Bleed the brake system.
Attention: Perform a safety compliance check:
- Are the brake hoses tightly tightened?
- Is the brake hose in the holder?
- Are the air bleed valves tightened?
- Is there enough fluid in the brake system?
- With the engine running, perform a seal weld. To do this, apply a force of 200 to 300 N to the brake pad for approximately 10 seconds (from 20 to 30 kg). Do not release the brake pedal. Check all connections for leaks.
Note: Handle brake fluid as special waste.
[This article is based on information from the website bmwman]