Knowledge and Help needed !!

[FUNKSTER UK]

Today I fitted new grooved front discs in hope to cure a brake vibration I've had since buying the car. I always believed the offside disc to be the problem as when you spun the wheel by hand whilst the car was on a jack you could here the intermittent chaffe of the disc to pad. After fitting the new discs I still had the chaffing and when torqueq up and taken for a run I still have the problem..........

The question is whats more likley to be running out of true, The disc mounting bell or the Hub.
I have read about the boys at pumabuild who can skim the discs on the car and therefore reduce the problem but I am not keen on grinding away my new brake disc to reduce the problem. I will get access to a dial guage before next weekend but am keen to know of other owners similar problems.

Thanks Matthew.

[F.C.]

FUNKSTER UK said:

Today I fitted new grooved front discs in hope to cure a brake vibration I've had since buying the car. I always believed the offside disc to be the problem as when you spun the wheel by hand whilst the car was on a jack you could here the intermittent chaffe of the disc to pad. After fitting the new discs I still had the chaffing and when torqueq up and taken for a run I still have the problem..........

The question is whats more likley to be running out of true, The disc mounting bell or the Hub.
I have read about the boys at pumabuild who can skim the discs on the car and therefore reduce the problem but I am not keen on grinding away my new brake disc to reduce the problem. I will get access to a dial guage before next weekend but am keen to know of other owners similar problems.

Thanks Matthew.

My car had the same problem before I bought it (M400), the garage replaced the bell on front RHS IIRC.
Sorted the problem, still good to this day though I had AP grooved dics fitted about a year ago.
F.C.

[peterguk V6 KWK]

I had the same vibration for over 6 months. Neither the factory nor a very well known specialist could sort it.

I spent a whole day unseizing my pads (corossion under the pad spring clips), new pads and discs and guess what? No vibration

See my post here fro details:

http://pistonheads.com/gassing/topic.asp?h=0&t=488848&r=7186077&hm=59677#7186077 

BTW, i have some CarboTech PantherPlus and XP8 pads on their way. 3 car sets of each, if anyone would like to try them..

Edited by peterguk V6 KWK on Sunday 6th April 13:17

[RobP]

FUNKSTER UK said:

Today I fitted new grooved front discs in hope to cure a brake vibration I've had since buying the car. I always believed the offside disc to be the problem as when you spun the wheel by hand whilst the car was on a jack you could here the intermittent chaffe of the disc to pad. After fitting the new discs I still had the chaffing and when torqueq up and taken for a run I still have the problem..........

The question is whats more likley to be running out of true, The disc mounting bell or the Hub.
I have read about the boys at pumabuild who can skim the discs on the car and therefore reduce the problem but I am not keen on grinding away my new brake disc to reduce the problem. I will get access to a dial guage before next weekend but am keen to know of other owners similar problems.

Thanks Matthew.

Get them to check run-out on the hubs - I suspect it might be this. I had bad vibration from mine and new discs disn't cure it. Run-out on front hubs was found to be around 14 thou (should be +/- couple of thou I believe). Hubs were replaced and new disks were skimmed(this was a precautionary measure as the old hubs could have put high points on the new discs. After that everything was perfect - absolutely rock solid, vibration-free braking.