Leak Test
WARNING: This page is about a different car, the 2013 Acura MDX, 2012 Acura MDX, 2011 Acura MDX, and 2010 Acura MDX. However, it is still accessible from the selected car via links, so may be relevant.
- Press the brake pedal with the engine running, then turn the ignition switch to LOCK (0). The brake pedal height should not vary while pressed for 30 seconds.
- If the pedal height rises, go to step 6.
- If it does not rise, go to step 2.
- Start the engine, and let it idle for 30 seconds. Turn the ignition switch to LOCK (0), and wait 30 seconds. Press the brake pedal several times using normal pressure. When the pedal is first pressed, it should be low. On consecutive applications, the pedal height should gradually rise.
- If it rises, the booster is OK.
- If it does not rise, go to step 3.
- Disconnect the brake booster vacuum hose (A) at the booster. The check valve (B) is built into the hose.NOTE: If the check valve is faulty, replace the brake booster vacuum hose and the check valve as an assembly.
- Start the engine, and let it idle. There should be vacuum available.
- If no vacuum is available, the check valve is not working properly. Replace the brake booster vacuum hose and check valve, and retest.
- If vacuum is found, go to step 5.
- With the ignition switch in LOCK (0), reconnect the vacuum hose to the brake booster.
- Start the engine, and then pinch the brake booster vacuum hose between the check valve and the booster.
- Turn the ignition switch to LOCK (0), and wait 30 seconds. Press the brake pedal several times using normal pressure. When the pedal is first pressed, it should be low. On consecutive applications, the pedal height should gradually rise.
- If the pedal position does not vary, inspect the O-ring between the master cylinder and booster. If the O-ring is OK, replace the brake booster.
- If the pedal position varies, replace the brake booster vacuum hose and the check valve as an assembly.