Metal rubbing on metal squealing noise

[racerwannabe]

Hi there, my car just started to make this really worrying noise front the front brakes/wheels.. i think. This noise only starts when the car is moving and its pretty constant as well. It doesn't happen when i break though. It sounds to me like metal rubbing on metal squeal. I have checked the brake pads and they are no where near worn out. Can anyone think of why this is occuring? Cheers.

[Psy]

Probably pads don't have a wide enough gap and they are touching the brakes constantly.

I remember my previous Holden car, the pads kept touching the brakes which was weird, but i fixed it in the end.

Again, it could be a totally different problem.

[racerwannabe]

i took the driver front wheel off and rotated the front disk. It squealed terribly..like finger nails running down a blackboard but it was more metallic sounding. Anyways to cut it short, it was the disk backing plate/shroud that was bent in towards the disk a bit too much. After i bent it back slightly the noise disappeared! :D I took it for a test drive and no noise whatsoever. Hope this will be useful if someone else encounters a similar noise.

[JohnL]

i took the driver front wheel off and rotated the front disk. It squealed terribly..like finger nails running down a blackboard but it was more metallic sounding. Anyways to cut it short, it was the disk backing plate/shroud that was bent in towards the disk a bit too much. After i bent it back slightly the noise disappeared! :D I took it for a test drive and no noise whatsoever. Hope this will be useful if someone else encounters a similar noise.

That will be the 'squealer', which is a little tab of metal designed to rub on the edge of the rotor and make a squealing / screeching noise (horrible!) in order to warn you that the pads are getting close to worn out. You can bend them back for temporary relief, but your pads are due for replacement, if not now then quite soon.

If the squealer wasn't there then unless you check the pads regularly you might have not known until the backing plates were grinding the bejeesus out of the rotor. They sound awful but they are your friend...

[racerwannabe]

Thanks John but there seems to be plenty of pad left. I will check again and maybe replace them to be on the safe side.

[BiLL|z0r]

I have/had a very similiar noise from the same area. If I brake it usually stops and only noticable at low speeds. Sounds like a rock is in there but happened way too often to be a rock. Honda service checked it out and said nothing was stuck there and heaps of pad left. I don't think it's done it since thogugh so it simply could have been the act of pulling it apart and putting back together that fixed it.

[JohnL]

Thanks John but there seems to be plenty of pad left. I will check again and maybe replace them to be on the safe side.
There may well be a fair bit of pad left, but keep in mind that the manufacturer will tend to be quite conservative on pad thickness. Thinner pads, even with a significant amount of friction material left will tend to lose efficiency as they get nearer the backing plate even if they're not actually worn out.

I've replaced pads with at least 3 or 4mm of pad remaining, and once bedded in the difffrence in braking performance was quite noticable with the new pads, and this was replacing old pads with the same brand etc new pads. Keep in mind also that as pads wear down they typically become 'tapered', i.e. thinner on some parts and thicker in others, and this also tends to lessen performance.

Taper wear on pads also cause increased pedal motion because more movement at the caliper pistons is required to take up any gaps between the rotor and the pads, and bring the pads into hard contact with the rotor

[JohnL]

I have/had a very similiar noise from the same area. If I brake it usually stops and only noticable at low speeds. Sounds like a rock is in there but happened way too often to be a rock. Honda service checked it out and said nothing was stuck there and heaps of pad left. I don't think it's done it since thogugh so it simply could have been the act of pulling it apart and putting back together that fixed it.

As you apply the brakes the position of the pad changes, especially if the pads are taper worn. If the squealer is only just contacting the rotor when the noise is occuring this may cause the squealer to lose contact with the edge of the rotor and the noise to cease, either while the brakes are applied and perhaps for some time afterward. How hard the brakes are used in any given brake application will probably also influence this. Pulling the pads out and re-installing them may be enough to temporarily cause the noise to cease completely.

[Pumped]

This noise is NOT caused by brake pads, i know the brake pad noise they make when the "squeeler" is rubbing its a really high pitch intermittent noise and generally stops making the noise when the brakes are applied, and i know the noise hes talking about its different its got more of a whistle/squeel to it rather then a high pitch almost ball bearing like noise the pad wear indicator makes

It happened to my car when it was only like 3 weeks old, brakes barely used..
as he said its the backing/dust plate behind the disc was rubbing and went bent back very slightly the noise completely stopped and has never came back, was only the front left for me.