Removing Brake Master Cylinder

Information 

• Before disconnecting the brake lines, place a clean absorbent cloth underneath  .
• Close off brake lines with a suitable plug immediately after disconnecting  .

Information 

• In the event of assembly work at the hydraulic connections, all electric plug connections in the area of the connection point must always be connected. This prevents the inside of the plug connections from being splashed with brake fluid or water  .
• Clean any plug connections that have become dirty or damp during removal and fitting using a lint-free cloth, for example  .
• Brake fluid on electrical contacts (even thinned brake fluid) leads to corrosion and may cause faults in the system  .
• Remove any escaping brake fluid immediately; rinse with water and dry thoroughly if necessary  .

1. Empty the brake fluid reservoir. To do this, pump out the brake fluid using a front and rear brake calliper.

   To pump out the brake fluid, open the bleeder valve and press the brake pedal cyclically. Use a collecting bottle.

2. Loosen the brake lines on the brake master cylinder.
   1. 2.1. Unscrew cap screws -4-  .
   2. 2.2. Pull brake lines out of the bores.
   3. 2.3. Immediately close off brake lines and bores in the brake master cylinder with suitable stoppers.
3. On vehicles with manual transmission: Pull off lines (to the clutch master cylinder and return line from the clutch slave cylinder) at the brake fluid reservoir.
4. Release and pull off plug connection -3-  (for brake fluid level indicator).

   Loosen the fastening screw (Torx E7) -2-  on the brake fluid reservoir (generally). As a result, the brake fluid reservoir -1-  (unless it is removed) can be tilted slightly towards the inside of the vehicle. The upper fastening nut -5-  on the brake master cylinder is then accessible and can be loosened.

   Fig 1: Identifying Brake Lines And Fasteners

   Courtesy of PORSCHE CARS NORTH AMERICA, INC.
5. If the brake master cylinder is replaced, remove the brake fluid reservoir -1-  from the brake master cylinder. Place suitable cloths underneath.

   Pull off the brake fluid reservoir -1-  or lever it out of the brake master cylinder using a suitable tool.

6. Unscrew fastening nuts -5-  on the brake master cylinder. Tilt the brake fluid reservoir -1-  (unless removed) slightly towards the inside of the vehicle while doing this so that the upper fastening nut -5-  can be loosened.

   Carefully remove the brake master cylinder from the brake booster.

Fig 2: Identifying Brake Master Cylinder
Courtesy of PORSCHE CARS NORTH AMERICA, INC.