Note: Before you begin, read the brake fluid hazard warning at the beginning of this manual paragraph 2.
Removal
1. On left-hand drive models, remove the battery and battery tray. as described in chapter 5A. Depending on the model and work space, to facilitate access to the master cylinder, remove the air filter and the remaining components of the air intake duct as described in the relevant section chapter 4.
2. Unscrew the cap on the filler neck of the brake fluid reservoir and use a suitable syringe or pipette to pump out the brake fluid from the reservoir.
Note: Do not suck out brake fluid by mouth as it is poisonous.
3. Disconnect the electrical connector of the fluid level sensor on the wall of the tank and release the electrical wiring from the corresponding clamp.
4. Place an absorbent cloth under the master cylinder to collect any leaking fluid and be prepared for brake fluid to leak out.
5. Wipe clean the area around the brake line fittings on the side of the master cylinder. Mark the location of the connections, loosen the union nuts/bolts and carefully remove the pipes. If "banjo" type fittings are used (with a hollow bolt), remove the copper washers located on each side of the connection and purchase new washers for installation. Properly plug the ends of the lines and the master cylinder ports to minimize brake fluid leakage and prevent dirt from entering the system.
6. Remove the two nuts securing the master cylinder to the brake booster and then remove the master cylinder from the brake booster. If the O-ring located at the rear of the master cylinder shows signs of damage or deterioration, it should be replaced.
7. If necessary, you can remove the hydraulic reservoir from the master cylinder. To secure the reservoir to its standard location, different methods are used depending on the type of master cylinder. This may be a combination nut, bolt and retaining clip located under the master cylinder, a roll pin, or a retainer and clip. Remove the appropriate fastener, then pull the reservoir up and out of the two sealing bushings in the master cylinder.
Repair
8. Before deciding to repair the master cylinder, make sure you have the necessary spare parts available. Although Peugeot/Citroen dealers supply interior components for some (but not all) used master cylinders, there is a possibility. that the repair kit can be purchased at auto parts stores. Purchase the correct repair kit for the master cylinder you are working on. Mark the location of all components to ensure proper installation and lubricate the new seals with clean brake fluid. Follow the assembly instructions included with the repair kit.
Installation
9. Carefully install the brake fluid reservoir into its original location (if it was removed), making sure it is installed correctly in the rubber bushings. Install the appropriate fasteners to secure the reservoir to the master cylinder.
10. Install the master cylinder onto the brake booster, ensuring that the booster pushrod is centered in the master cylinder bore. Install the master cylinder mounting nuts and tighten them to the specified torque.
11. Wipe the brake line fittings clean, connect them to the master cylinder ports and tighten securely. If "banjo" type fittings are used (with a hollow bolt), install new copper washers on each side of the connection.
12. Connect the electrical connector of the brake fluid level sensor and secure the wiring with a clamp.
13. On left-hand drive models, install the battery tray and battery (see chapter 5A). Install the air filter and air intake duct components removed for access as described in the relevant section chapter 4.
14. Fill the brake fluid reservoir with fresh fluid and bleed the entire hydraulic system as described in paragraph 2.