Master brake cylinder (Hyundai Sonata EF)

Removal

1. Disconnect the brake pipes from the master cylinder. Install plugs on the open holes.

Caution: Do not allow brake fluid to come into contact with painted surfaces. If brake fluid does come into contact with a painted surface, wash it off immediately.

2. Loosen the nuts securing the master brake cylinder and remove the cylinder.

Disassembly

1. Remove the brake fluid reservoir cap and drain the brake fluid into a suitable container.



2. Using a screwdriver, disconnect the reservoir from the master brake cylinder and remove the sealing bushings.

The article is copied from this website [HyundaiBook]

Note: Do not press the brake pedal while bleeding the brake system.

3. Using a special puller, remove the retaining ring.



4. (Models with ABS) Remove the piston stroke limiter.

5. Remove the primary piston assembly.

6. (Models with ABS) Using a screwdriver, remove the piston stroke limiter.



7. Remove the secondary piston assembly.

Note: Do not disassemble the pistons.

Examination

1. Check the inner surface of the master cylinder housing for rust and scuff marks.

• Nominal inner diameter of master cylinder: 23.8 mm

2. Check the primary and secondary pistons of the master cylinder for rust, scoring, wear and damage.

Note:

• If the inner surface of the master cylinder housing is damaged, replace the master cylinder assembly.
• Wash the master cylinder parts with alcohol.

Assembly

1. Lubricate all rubber parts of the brake master cylinder kit and sealing bushings with clean brake fluid.



2. Carefully install the springs and pistons into the master cylinder.

3. Press the piston with a screwdriver and install the retaining ring.



4. Press the piston until the spring is fully compressed and set the piston stroke limiter.



5. Install the sealing bushings.



6. Install the brake fluid reservoir onto the master cylinder.

Installation

1. Check and adjust the rod length if necessary.

• Tightening torque: 8.25±0.125 mm

2. Install the master cylinder onto the brake booster and tighten the two nuts.

• Tightening torque: 8-12 Nm

3. Connect the brake pipes to the master cylinder.

• Tightening torque: 13-17 Nm

4. Fill the reservoir with brake fluid, then bleed the brake system.