Brake question ?????

Question

when i apply pressure to the brakes and release them i hear a hissing sound as if air is being released and the pedal slowly rises back up, can anyone tell what my problem could be ?

Answer 1

Sounds like a leak in the vacuum booster.

Answer 2

I am thinking a leak in your brake line, but I could be wrong?

Answer 3

I think you might need a new one dude, happened to my mom.

Answer 4

could be your brake booster cuz the hissing noise means that you are loosing your vacuum.

Answer 5

If the way the brakes work has not changed, i.e the pedal has gone harder to press, you can get some hissing noise from the brake servo as it works on vacuum to assist the braking.

My pedal hisses on pressing the pedal which is not unusual, just get the servo and servo pipes checked if you cant do yourself. the servo should be able to hold a vacuum and not leak.

Answer 6

How is the break fluid?

Do you have air in the line?

did you just have the breaks done and blead them?  

Answer 7

your brake booster is going bad. its the dome looking thing behined the brake fluid resevoir. Its a common issue when a car gets a little older. You can buy rebuild units from most auto parts stores and do it yourself fairly easy if you have any mechanical ability and tools. For a repair shop to replace it it should cost anywhere between $150.00 to $300.00 depending on what type of vehicle and what their labor rates are.

Dont worry you wont just loose your brakes one day. It will get worse with time but should never just fail out on you. when you find you need to pump the brakes every time to get a decent petal, its time to get it changed sooner rather than later.

Good Luck!