Brake Master Cylinder Repair

Lead Image
  • 2-4 hours
  • Advanced
  • 100-500
What You'll Need
Brake master cylinder kit
Line wrench
Socket wrench
Snap Ring Pliers
Brake fluid
Brake fluid removal tool

The most common necessary brake master cylinder repair is fixing a leak in the seals. This is typically a brake master cylinder repair that will become necessary after a few years when the seals wear out. It’s not a difficult repair, although the details might vary depending on the make and model of your vehicle.

Step 1 - Prepare

Park your car on a flat surface. Make sure the vehicle is in park with the emergency brake on. Spread layers of old newspaper under the engine to catch any brake fluid that drips. Use a brake fluid removal tool to take out the fluid from the reservoir until it is empty. At this point, you’re ready to actually begin your brake master cylinder repair. Unclip the sensor from the reservoir.

Step 2 - Remove the Master Cylinder

To remove the brake master cylinder, use the line wrench to loosen the brake lines and remove them. This tool will do a better job than a regular wrench. When you’ve done that, locate the bolts holding the master cylinder to the body of the vehicle. You’ll need to use your socket wrench to loosen and remove these. Lift the master cylinder out of the car, and plug the holes for the brake lines with clean cloths.

Step 3 - Disassemble

Take the brake master cylinder to your workbench for the rest of the brake master cylinder repair. You’re going to need to remove the reservoir from the top of the cylinder first. For this you’ll need to just snap it off with a screwdriver. Now, look at the rear of the master cylinder. You’ll see a lock ring that keeps the pistons in place. Remove this with snap ring pliers. After that, take out the retaining ring that keeps the valve from the reservoir in place and remove the valve.

To access the pistons, valve assemblies and the seals for the brake master cylinder repair, tap the cylinder on your workbench and they will slide out. Keep them safe along with all the springs.

Step 4 - Assemble

Find the correct seals in the brake master cylinder kit. Replace them in the pistons, and carefully reassemble the pistons in the master cylinder, ensuring you put all the parts fit in correctly. Replace the retaining ring and then the lock ring before snapping the reservoir into place and putting the lock ring into place.

Now, sit the brake master cylinder back in place in the engine and replace the bolts to hold it firmly to the vehicle body. Reattach the brake lines and fill the master cylinder with brake fluid.

Step 5 - Bleed the Brakes

You haven’t finished your brake master cylinder repair yet. The most important step is to bleed the brakes so they’ll work well. You’ll need help to do this properly, as you operate the brakes and someone else opens and closes the bleeder valves on each wheel until there’s no more air in the system and the fluid is clear. After that, you’ll fill up the reservoir again and check if the brake pedal operates normally before driving the vehicle.