Symptoms of a bad brake booster
The brake booster is the most important part that helps the driver's comfort. The brake booster serves to help relieve the brake pedal when we brake. That way, our feet don't get tired and sore when driving, especially in traffic jams.
Although at first glance it only aims to increase comfort while driving, the brake booster has a crucial function for the car's brake system.
Without a brake booster, our feet become sore quickly and can cramp to be dangerous. In addition, a damaged brake booster will also reduce the car's ability to brake and stop as we wish.
The most common cause of a damaged brake booster is the brake booster leaking air. So what are the brake booster symptoms that arise in the car if it leaks? Check out the symptoms of a bad brake booster below.
1. Brake pedal feels stiff when stepped on.
The brake booster symptom that we most quickly feel when it leaks is that the brake pedal feels stiff and tight when you step on it. A leaky brake booster can cause symptoms that the brake pedal feels stiff and heavy when you step on it; the car brakes feel less grippy and slower to stop.
This condition will be very much different if the brake booster is in normal condition. When the brake booster is normal, the pressure to step on the pedal will not feel stiff and heavy. In addition, the car's brakes will also feel more responsive and gripping.
The brake booster leak causes the loss of vacuum in the vacuum chamber. The vacuum power used to help push the pushrod on the brake pedal is lost. As a result, we need to spend more extra power to cover the power lost when the brake booster leaks.
2. A hissing sound appears when the brake pedal is stepped on.
The other brake booster symptom that we most quickly feel when it leaks is when the brake pedal is stepped on. Yes, the brake booster has a vacuum that should not leak. This vacuum chamber serves to pull the inner membrane of the brake booster to reduce tread force.
A hissing sound will appear when the air valve on the brake booster opens. That is when the brake pedal starts to be pressed.
There will be free air suction from the outside when this vacuum leaks. The outside air will suck into the brake booster until it reaches the engine intake manifold. The free flow of air entering the intake manifold will cause a strong hissing sound that we can hear when the brake booster leaks.
Read also:3. The engine vibrates when the brake pedal is stepped on.
In addition to a hissing sound, a leaking brake booster will also cause the car engine to vibrate when the brake pedal is stepped on. It vibrates in rhythm with the appearance of a hissing sound when the brake pedal is stepped on.
When an air leak occurs from the brake booster, the amount of air entering the engine cylinder no longer matches the MAF sensor reading (for injection cars). Or, it is no longer fits the throttle valve opening (carburetor type).
This condition will cause the air and fuel mixture to be no longer suitable. The effect will make incomplete combustion in the engine. Incomplete combustion gives the engine a vibrating effect, one of which is due to this leaky brake booster.
4. The engine idling rpm becomes unstable.
In addition to when the brake pedal is stepped on, a leaky brake booster can also cause the engine idling rpm to become abnormal, up and down, until the engine is difficult to start. When this condition occurs, the brake booster usually leaks enough to spread out of the valve.
If a leak in the brake booster occurs until it exits the valve, we can hear a hissing sound without the brake pedal being stepped on. In addition to the sound, the engine also becomes difficult to slow down, and the engine rpm is not stable.