Is there a grinding sound too? You may need new breaks. Take them to someone who knows about this stuff before they fail.
By the hissing noise it sounds like you need a new brake booster
The power brake booster may be going bad.
This one is easy. Brake booster diaphragm is ruptured, causing a massive vacuum leak, which will cause the engine to run poorly when the brakes are applied. A loss vacuum assist will make it difficult to stop the vehicle.
No. The brakes are applied manually. A brake band squeezes a brake drum.
The power brake booster is shot.
No. If you put your foot to the brakes, it will come on. -Answed By Brain!! :))
When the brakes are applied, the car's kinetic energy is converted to heat by friction between the brake pad and the brake disk.
Brake linings need replacing? Vacuum leak?
This is probably due to worn brake rotors on the brakes, if there is no vibration when driving then this will be the cause.
Power brake booster is going bad. wont hold vacuum for power brakes to work.
Your brake rotors are warped and need replaced/resurfaced.
The power brake vacuum booster is probably failing.