Lesson 3.9 – Brake Booster and Master Cylinder Copy


Approximate time to complete this lesson: 10 minutes.

Lesson 3.9 Video

To begin Lesson 3.9, watch this video (2 minutes, 34 seconds).


Review of Lesson 3.9


  1. Pump brake pedal 20-30 times in order to discharge the ABS system.
  2. Disconnect any sensors or wires attached to master cylinder. Do not cut any wires.
  3. Disconnect all brake lines from master cylinder.
  4. Disconnect the brake pedal from brake booster located under the dash.
  5. Unbolt four bolts under dash located by brake pedal holding the booster in place.
  6. Slide the assembly from the fire wall.
  7. Take the assembly to the dismantle bench in order to remove the master cylinder from the booster.
  8. ABS modules can be removed in the same manner depending on the vehicle: see model information.

Quality Control:

  1. This may not be a requirement for some later model vehicles. If you are unsure, it is recommended that you do so regardless.
  2. Place a catchment tray under the part to collect any residual oil.
  3. Check work order to see if this comes in an assembly or individual pieces.
  4. Basic tools required.

Health & Safety:

  1. Standard PPE applies.
  2. Risks:
    – Risk of cuts
    – Awkward position under the dash

The next lesson (topic) is Brake Rotors