Brake Booster (For Hatchback) On-Vehicle Inspection

Airtightness check

1. Start the engine and stop it after 1 or 2 minutes. Slowly depress the brake pedal several times.
   

   HINT:

   1. If the pedal can be depressed to the floor the first time, but on the 2nd and 3rd times cannot be depressed as far, the booster is airtight. If not, inspect the vacuum check valve.
      
   2. If the vacuum check valve is normal, replace the brake booster assembly.
      

2. Depress the brake pedal while the engine is running, and stop the engine with the brake pedal depressed.
   

   HINT:

   1. If there is no change in the pedal reserve distance while holding the pedal for 30 seconds, the booster is airtight. If not, inspect the vacuum check valve.
      
   2. If the vacuum check valve is normal, replace the brake booster assembly.
      

Operation check

1. Depress the brake pedal several times with the ignition switch off and check that there is no change in the pedal reserve distance.
   





2. Depress and hold down the pedal, and start the engine.
   

   HINT:

   1. If the pedal goes down slightly, operation is normal. If not, inspect the vacuum check valve.
      
   2. If the vacuum check valve is normal, replace the brake booster assembly.