1. Start the engine.
2. Stop the engine after running for 1-2 minutes.
3. Depress the brake pedal several times and observe the pedal travel. If the pedal travels far the first time, but the travel decreases during successive depressions, air tightness is obtained.
4. If pedal travel doesn't change, air tightness is not obtained. Perform the following procedure.

4.1.	Inspect the vacuum lines and the sealing parts.

4.2.	Replace any faulty parts.

4.3.	Repeat the entire test.

Inspect Brake Pedal Operation

1. With the engine stopped, depress the brake pedal several times and verify that the pedal travel doesn't change.
2. Start the engine while depressing the brake pedal. If the pedal travel increases a little, operation is satisfactory.
3. No change in pedal travel indicates a malfunction.

Inspect Air Tightness Under Load

1. With the engine running, depress the brake pedal.
2. Stop the engine while holding the brake pedal depressed.
3. Hold the brake pedal depressed for 30 seconds. If the pedal height does not change, the condition is good.
4. If the pedal rises, the condition is poor.