I have a 1998 Chrysler Concord with over 14k miles which has developed a problem recently. When I step on the brakes it makes a sound like a valve opening letting air out. The sound clearly comes from the inside of the car.The brakes still work but the sound of air coming out of the brake pedal is mystfying.
You have a ruptured power brake booster diaphragm. It’s a pretty easy fix and shouldn’t be that expensive (as brake repairs go). It is something that you should have checked out because it’s causing a vacuum leak and it’s reducing the amount of braking power that you have.
Best of luck.
Does the noise stay as long as you hold the brake down, or just when the brake pedal is moving?
It makes the noise onl when the pedal is moving, but as of yesterday it is no longer making the noise - very odd indeed.
Are you sure it is not normal. All cars with power brakes make a very slight hiss sound as the brake pedal moves. In most cases, you have to listen carefully to hear it, but in some cars it is pretty noticeable. Usually, there is some kind of sponge like filter to reduce the noise. Maybe yours is loose?
Usually, there is some kind of sponge like filter to reduce the noise. Maybe yours is loose?
Get up under the instrument panel and find the rod that connects the brake pedal to the booster. Where this rod goes into the firewall should material like felt or sponge. See if it’s backed out and tuck it back up in.