SimonK

When car cold = zero noise. Once warmed up this is the sound at the front left wheel as I press on the brake pedal. ? Some kind of shield noise? Anti squeak plate?

http://www.communicormedia.com/brakenoise.mp3

LVDell

Sounds like sex on a squeaky bed

SimonK

Yep. :-). Any ideas though?

LVDell

Is that really coming from the left front brakes? Where is the recording taken from?

Macster

This noise is not a common one based on my experience.

I note too you are in the UK. There have been more than a few reports of brake rotors rusting/corroding -- especially on the inside rotor surfaces -- that the brake rotor surface begins to shed flakes of metal.

Thus I think you should consider removing the wheel and give the brake hardware a good inspection. If you do not feel up to this or want a professional's opinion, then take the car to a shop and have it done. Brakes are nothing to skimp on and I always advise one err on the side of caution when dealing with possible brake problems.

Are you pushing then releasing the brake pedal to create that noise and the car is stationary, or is the brake pedal being applied while the car is moving?

If the former and assuming the noise is not being recorded from inside the cabin (which would then strongly suggest the noise was coming from the brake hardware in the cabin, the brake linkage) that sounds like one or both pads are moving in with the depressing of the brake pedal (which they should) and moving back out again (which they should -- from the brake piston seal hysteresis) and doing so there's some rubbing by the pads against the expanding spring.

Normally this movement is small. The seals only retract the pistons a tiny bit from the surface of the rotors most of the time just enough so there is no rubbing and thus while the car is moving and the brakes are not being applied there is no noise.

If the brakes get dirty and if the car is driven the brakes get dirty the pistons/pads are not always retracted quite far enough and one or more pads will drag against a rotor and the brakes will squeal faintly when the brakes are warm and the car driven at slower speeds. I've found a 'cure' for this is to simply wash the brakes. I use a DIY car wash and set the wash wand first to 'soap' (not the brush/suds setting) and then the rinse settting.

While washing or rinsing I avoid jamming the tip of the wand right up against the brake pads. I get it close, but not close enough to possibly tear the piston dust covers and force water into the brakes.

Sneak up on the brakes with the wand and at some point you'll see dark water running off the wheel. This is the dust you want to remove. Vary the wand angle to hit the brake calipers from both the front and the rear.

(A side note is if the brake rotor holes are dirty have started to collect a build up of dust, you can use the wand to wash this dust out of the holes. You will have to get the holes that are exposed first then move the car forward a few feet to expose the holes of the rotor that is between the pads so you clean all holes of any dust.)

I use the spot free rinse setting to rinse the soap off the hardware cause this setting the water pressure is lower. In this setting I rinse the inside of the wheels and give the wheel well lining a good spraying to clean the liners.

Afterwards, I drive the car and use the brakes enough to get them hot enough to dry the hardware thoroughly. You do not want to leave the brakes wet.

But the noise does not sound to me like the brakes are dirty, but more that the brake pads are moving in and out by more than the tiny bit they normally do. This does suggest to me that the rotor surface has suffered some degradation possibly do to corrosion.

Another possibility (less likely) is that something got caught in one of the rotor's holes and is brushing against the brake pad and making the noise.

I'd be interested in knowing what you find is the cause of the noise.

Sincerely,

Macster.

SimonK

The noise is recorded 3 inches from the front wheel facing the brake calliper. Car is at a stop, engine running. I am pressing and depressing the pedal – that is what's heard on the recording. I have newish discs and pads - 10K. When car is cold - no noise, once warmed up this springy noise appears. I have jet washed the brake area – the discs thoroughly clean. I have no idea what this could be... weird, will report back.

LVDell

Could be something as simple as the top of the metal backing plate sliding under the metal retaining spring clip. Are you able to visually isolate the sound source?

dantzig

First thing I'd do: Remove LF wheel, and have someone sit in the car and pump the brake pedal while you get a listen from up closer.

My guess is the pad stick-slipping on the tensioning spring. If that is it, you could fix by removing the pads, and running some steel wool over the edges of the pads that bear against the spring, and the spring itself, then reassembling.

Jon

SimonK

Thanks guys. Will do. Will report back on findings.

SimonK

Update on brake madness. Had brakes inspected. Noise definitely coming from the calliper. Brakes working fine. Disks fine, pad wear uniformed (so sticky piston ruled out). We took the spring out, pads out, anti squeak plates out cleaned everything – same story. We then even filed down pad corners and anti squeak plates by 1/2mm (all corners) to make sure nothing is rubbing - the noise remains. The noise is not present when brakes are cold. Once everything reaches operating temps noise is back. Can’t trace it! Any other ideas?

Here is the noise again - recorded next to the wheel. Car off brake pushed in all the way. At the end of travel, full on the brake (pressing, releasing) - here is the noise.

http://www.communicormedia.com/brakenoise2.mp3