e_kobz

iTrader: (36)

So I'm at a complete loss right now. I recently installed a new set of pads and fluid on my Evo IX track car before this past weekends NASA event and now whenever I apply the brakes I hear a air leak sound coming from the front of the car. It's not very loud but I can hear it when driving slow. On the street or track its too noisy and everything else drowns out the noise. The brake pedal is still pretty firm, it never goes to the floor, so I know theres pressure in the system and the car still stops on a dime. But I know that sound should not be there as it was never there before. I have checked all brake lines and bleeder valves and nothing is leaking, not air or fluid. None of the lines in engine bay connecting the brake maser cylinder to the ABS module are leaking. My only thought at this point is the gasket between the brake master cylinder and the brake booster could be leaking. I ordered a new gasket, hopefully that'll take care of it. But has anyone else experienced this? Any other suggestions?

e_kobz

iTrader: (36)

For reference my brake setup is stock calipers, stainless steel lines, Motul RBF600 fluid, Raybestos ST43 pads up front, and Ferodo DW2500 pads in the rear

barneyb

Drive through an underpass in the outer lane with the windows down. If the sound gets louder you have a brake dragging.

e_kobz

iTrader: (36)

It's not dragging brakes. The sound only happens with the brakes are applied. The sound goes away as soon as I let off the brakes

MinusPrevious

iTrader: (3)

Could it be a dust shield contacting the rotor. Their so easy to bend when doing brake work.

LetsGetThisDone

iTrader: (1)

Are you sure it isn't just the noise of the brake pads touching the rotor? I know some brakes pads make a rubbing "ccchhhhhhhhhhhhh" noise that's not unlike an air leak "hissing" type sound..

e_kobz

iTrader: (36)

It doesn't sound like metal on metal contact

LetsGetThisDone

iTrader: (1)

Right, it doesn't. It just sounds like brake noise. I think you're just hearing the noise the friction material makes against the rotor, and that's it..

e_kobz

iTrader: (36)

If that's it that would be great lol

Pal215

iTrader: (12)

If it only makes the sound while the car is moving then it's most likely from the rotors/pads. If you can hear the noise while your at a stand still and pressing the brakes, then you might have a vacuum leak at the brake booster hose.

-pal215

e_kobz

iTrader: (36)

Yeah it's only when moving, no noise when sitting still. It probably is just the pad and rotor contact. I'm probably over thinking it. Thanks guys

barneyb

My guess is that you are hearing a little vibration in one of the brakes. If true, this will either go away with use or get worse. If it gets worse you should be able to tell which corner is the problem and give it a little more maintenance attention.

GTijoejoe

iTrader: (25)

This.

What type of rotors do you have? Any features like dimples or holes or slots?

e_kobz

iTrader: (36)

Slotted rotors