Wistling Noise From Car That Stops When I Brake

February 19, 2024

A whistling noise from your car that stops when you brake is usually an indicator that your pads, rotors or calipers are wearing out and need to be replaced. This is a common problem that can be quite dangerous if ignored since your car’s brakes are one of the most important safety features. This article will discuss the different possible causes of this whistling sound along with a few tips on how to diagnose and fix the issue.

A hissing sound from your brake booster may indicate that the foam silencer is missing or damaged. This is a small piece of foam that sits between the brake pedal and the brake booster, and it acts as a sound absorber to quiet the hissing noise from the booster when you push down on the brake. It can be easy to overlook this hissing noise, but ignoring it can lead to your brake booster or master cylinder failing.

Other hissing sounds can be caused by the brake disc rubbing against the rotor. This is a normal sound that is created when your brake pads are getting worn down and your brake wear indicator begins to rub against the rotor.

Another cause of hissing is a vacuum leak in the brake booster diaphragm, master cylinder gasket or vacuum hose. If you notice this problem, you will need to have a mechanic disconnect and plug the brake booster vacuum hose and then see if the hissing noise goes away (do not drive the vehicle while doing this). A leaking or disconnected vacuum hose can cause engine performance problems, so this is also something that should be addressed immediately.


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