Assuming you would like tips on how to tell if your brake booster is going bad:
One common symptom of a failing brake booster is a spongy or soft feel when depressing the brake pedal. If it feels like you're pushing the pedal through a wet sponge, there's a good chance your brake booster isn't working properly.
Other signs that your brake booster may be failing include:
• Your engine idle speed drops noticeably when you depress the brake pedal.
• It takes longer than usual for your vehicle to come to a stop.
• You hear strange noises coming from under the hood when depressing the brake pedal.
If you notice any of these symptoms, it's important to have your vehicle checked out by a qualified mechanic as soon as possible. A failing brake booster can cause serious braking issues that could lead to an accident.