Brakes: Does your brake pedal hiss at you?

[ww1dm1]

Alright, I'm slightly confused now. What about the others, does your pedal hiss?

Here's a recording of me pumping the pedal a few times, engine on. Keep in mind that this was taken near the pedal, so it's not THAT loud in normal sitting position, but definitely louder than in any other car I've driven. The pedal is also quite mushy, as I mentioned, so I guess extra pedal travel could make the noise much more obvious.

https://instaud.io/nhc

[ilikewatch]

Originally Posted by ww1dm1

Alright, I'm slightly confused now. What about the others, does your pedal hiss?

Here's a recording of me pumping the pedal a few times, engine on. Keep in mind that this was taken near the pedal, so it's not THAT loud in normal sitting position, but definitely louder than in any other car I've driven. The pedal is also quite mushy, as I mentioned, so I guess extra pedal travel could make the noise much more obvious.

https://instaud.io/nhc

I've never heard a noise like that from a brake pedal - have you checked to make sure there isn't an old set of blacksmiths bellows or bagpipes trapped under the pedal :-)

[skyship007]

Originally Posted by ilikewatch

I've never heard a noise like that from a brake pedal - have you checked to make sure there isn't an old set of blacksmiths bellows or bagpipes trapped under the pedal :-)

Umm! it sounds like a forked foot pump, which might mean the master cylinder is leaking. Not sure if you can make a mistake bleeding the brakes that would result in such a noise.

I would try visiting a good Indy or brake shop, BUT inform them that they will not be doing the repair work and all you need is an inspection and verdict. Otherwise they might say the front calipers, brake master and ABS pump all need changing!

[pierremcalpine]

Originally Posted by ww1dm1

Alright, I'm slightly confused now. What about the others, does your pedal hiss?

Here's a recording of me pumping the pedal a few times, engine on. Keep in mind that this was taken near the pedal, so it's not THAT loud in normal sitting position, but definitely louder than in any other car I've driven. The pedal is also quite mushy, as I mentioned, so I guess extra pedal travel could make the noise much more obvious.

https://instaud.io/nhc

Pretty sure that if I slam mine down, it hisses. The hissing stops once the pedal movement stops. Your problem is that you've corrected too many other issues and the car is now running way too smoothly.

[ww1dm1]

Originally Posted by ilikewatch

I've never heard a noise like that from a brake pedal - have you checked to make sure there isn't an old set of blacksmiths bellows or bagpipes trapped under the pedal :-)

I hoped to find an old tyre foot pump that I misplaced somewhere under the pedal, but sadly neither the footpump nor bellows were there.

Originally Posted by skyship007

Umm! it sounds like a forked foot pump, which might mean the master cylinder is leaking. Not sure if you can make a mistake bleeding the brakes that would result in such a noise.

I would try visiting a good Indy or brake shop, BUT inform them that they will not be doing the repair work and all you need is an inspection and verdict. Otherwise they might say the front calipers, brake master and ABS pump all need changing!

Exactly what I was thinking, sounds like an old foot pump. I'm not sure how you came to the conclusion about the master cylinder. As far as I know the main symptom of a leaking cylinder is a slowly sinking pedal upon pressure, shouldn't make any odd sound as well. Sound was there before bleeding and stayed after.

Originally Posted by pierremcalpine

Pretty sure that if I slam mine down, it hisses. The hissing stops once the pedal movement stops. Your problem is that you've corrected too many other issues and the car is now running way too smoothly.

I wish. Honestly, my main problem is the spongy pedal. There shouldn't be air in the system after bleeding the brakes (unless the cylinder needs bleeding?) and I was hoping that whatever that is causing this sound might be transforming my pedal into jelly as well. Is your pedal firm?

[pierremcalpine]

firm after a few pumps yes.

[ww1dm1]

Originally Posted by pierremcalpine

firm after a few pumps yes.

A few pumps? I mean with the engine on, it shouldn't need pumping.

[pierremcalpine]

Originally Posted by ww1dm1

A few pumps? I mean with the engine on, it shouldn't need pumping.

Sorry that was with engine off. You are correct, it is firm with engine on with acceptable travel.

[Worms]

Mine makes a similar noise and always has! Well, at least for the last 160,000 miles! I've always assumed that was normal!

[neanderthal]

could have a pin hole leak from the brake servo.hows your neck for checking up behind the brake pedal.i have had a bit of a soft pedal for quite sometime,and a very low hiss.