sounds like air is leaking when brakes are applied?

35068 Views 8 Replies 7 Participants Last post by green_hornet_96, Jan 14, 2007

bonus12

Discussion Starter · Jan 14, 2007

when i push in the brake pedal as far as it goes, i can hear something that sounds like leaking air. i know this doesnt make sense, but seomeone suggested that it might be fluid leaking. i checked my brake fluid, and it is fine. could it be leaking within the system?

also, my brakes are not good, and are due for a checkup, but they don't squeak, or chirp, when i brake.

and ideas about the leaking air sound?

Note: it is not very loud; it can only be heard when ambient noise is low (no music, stopped car, etc).

thanks in advance

Save

1 - 9 of 9 Posts

icarusdown

· #2 · Jan 14, 2007

that'd be you brake booster.
when the brakes are applied the booster equalizes pressure through a vent inside the cabin at the pedal pushrod. There's supposed to be a little foam 'muffler' in the vent. I think they deteriorate.

perfect little animation to show you

http://auto.howstuffworks.com/power-brake2.htm

Save

areskzc

· #3 · Jan 14, 2007

the booster may have a leak, check vacuum lines also!

Save

bonus12

Discussion Starter · #4 · Jan 14, 2007

icarusdown said:
that'd be you brake booster.
when the brakes are applied the booster equalizes pressure through a vent inside the cabin at the pedal pushrod. There's supposed to be a little foam 'muffler' in the vent. I think they deteriorate.

i think it is the brake booster, now that you mention it. would a failing brake booster cause the brakes to be worse? just making sure...

Save

asshat

· #5 · Jan 14, 2007

bonus12 said:
i think it is the brake booster, now that you mention it. would a failing brake booster cause the brakes to be worse? just making sure...

yes

Save

moz_21

· #6 · Jan 14, 2007

bonus12 said:
i think it is the brake booster, now that you mention it. would a failing brake booster cause the brakes to be worse? just making sure...

Yes and no. You won't have the 'assist' that the booster provides, but you will still have the same braking power (just have to press harder).

Save

icarusdown

· #7 · Jan 14, 2007

if it only makes the sound when you push the brake pedal, then it's working as designed. It's just old and making noise.

if the booster has gone bad then you would not have power assist and/or your engine would have a large vaccum leak. either of which are obvious.

watch the animation I posted.

Save

93reddelsol

· #8 · Jan 14, 2007

icarusdown said:
if it only makes the sound when you push the brake pedal, then it's working as designed. It's just old and making noise.

if the booster has gone bad then you would not have power assist and/or your engine would have a large vaccum leak. either of which are obvious.

watch the animation I posted.

The animation was to funny, lots of penetration.:TU:

Save

green_hornet_96

· #9 · Jan 14, 2007

If you want to really hear a power booster, test drive any 5-yr-old or older ford truck. Push that pedal down and all you hear is PSSSSSHHHHHHH.

Apparently they don't think it's worth their while to quiet it down, or the foam just breaks down real quick.

Save

1 - 9 of 9 Posts

This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.

Top Contributors this Month