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Brake vibration
beaver34 - 26/8/13 at 08:42 PM

Hi,

I have a vibration under braking through the wheel, it's done it since I put it back on the road this year after a couple in bits.

What are the normal reasons behind this? Checked for play in everthing and it seems fine

Any one had this before?

Thanks

Wheels244 - 26/8/13 at 08:51 PM

Warped discs ?

Bare - 26/8/13 at 08:52 PM

Typically caused by a brake rotor bouncing against the pads.... due to a warped rotor OR an ineptly mounted one.

YQUSTA - 26/8/13 at 09:21 PM

I had this on my Clio and from all the reading I did warped discs is almost a myth, normally it is the surface that the disc is mounted to that has an uneven surface which gives the impression that the disc is warped, I would start by taking them back off and cleaning the surfaces.

Wheels244 - 26/8/13 at 09:38 PM

Probably less common on modern vented discs, but I've definitely had warped solid discs before, used to put them in the lathe and skim them flat again if there was enough meat left on them.
Also my GPZ1000RX used to eat them - most definitely warped when I put them on the surface plate to check - not surprising really hauling 165mph bike to a halt with single piston calipers..

OP - check the run out with a dti if you've got access to one.

adithorp - 26/8/13 at 09:52 PM

quote:
Originally posted by YQUSTA
I had this on my Clio and from all the reading I did warped discs is almost a myth, normally it is the surface that the disc is mounted to that has an uneven surface which gives the impression that the disc is warped, I would start by taking them back off and cleaning the surfaces.


This ^^^

We get cars in all the time with this and although I have seem actual warped discs it's rare. Of course changing discs cures it but it wasn't the discs, just that the a faces were cleaned in doing it. The slightest rust or grit between the disc/hub can cause it.

Take the discs off and clean the hub faces and refit. Don't grease or copper-slip the faces (jsut a smear will be OK though not recommended) and re-build.

Smoking Frog - 26/8/13 at 10:16 PM

If the disc is not running true you can often feel the brake pedal pulsing as the disc forces the caliper piston back.

britishtrident - 27/8/13 at 06:10 AM

It could be a warped disc but more likely a deposit on the disc surface start by cleaning the discs with 80 grade production paper or one of those paint stripper pads that fit power drills. Don't be scared to scratch up the disc the aim is to get any deposits off the surface of the discs.

mcerd1 - 27/8/13 at 09:03 AM

quote:
Originally posted by adithorp
quote:
Originally posted by YQUSTA
I had this on my Clio and from all the reading I did warped discs is almost a myth, normally it is the surface that the disc is mounted to that has an uneven surface which gives the impression that the disc is warped, I would start by taking them back off and cleaning the surfaces.


This ^^^

We get cars in all the time with this and although I have seem actual warped discs it's rare. Of course changing discs cures it but it wasn't the discs, just that the a faces were cleaned in doing it. The slightest rust or grit between the disc/hub can cause it.

Take the discs off and clean the hub faces and refit. Don't grease or copper-slip the faces (jsut a smear will be OK though not recommended) and re-build.


^^ what they said, if the discs clean up well enough its most likely a bit of crud/rust stuck between the disc and the hub

personally I do use a little copper grease on the face of the hub (and on the face of the disc for the alloy to bolt to) but I just paint a thin smear with a paint brush - just enough to stop them all seizing solid for the next time you want them apart

if you are using some copper grease make sure you keep everything clean - its also good at collecting all the little rust flakes etc. (still worth it if your careful IMHO)