Brakes vibrating when hot
 

Fitted new grooved discs, ferodo 2500's & dot 5.1 brake fluid to my classic a few weeks ago.

Bedded them in gradually over a few hundred miles and all was fine for a while.

They've developed a problem now though, when they get very hot they vibrate like mad. Am I right in saying if the discs were warped they would vibrate all the time rather than just when they get hot?

Does anyone have any suggestions whats wrong with my brakes?

I have the same problem mate. Had my brakes looked at and was told they are fine and no warping. why they would start vibrating when hot is beyond me. Calipers etc are all fine too. Last time I try performance brakes - never had a problem with the brembos before.

Thats not the answer I was hoping for but cheeers anyway.

Not too sure whether to change back to flat discs or take out the ferodos, something has to change though coz its desperate vibration & I can't put up with it.

Might be pad deposits from overheating the pads. Have a look at the discs to see if they have a smeared/patchy appearance. If they have just drive normally for a while and it will wear off and brake a bit gentler in future.

Check you haven’t got a slightly sticking piston (usually on the inside fronts) I had it on mine same symptoms cleaned them up and its fine now :thumb:

i have just had a siezed piston on my front and when that got hot, the wheels vibrated

Might be worth checking for the piston thing

Jason

Cheers for the reply lads, am getting a couple of things done next week so will check for a sticky/seized piston.

Sounds similar to mine. Brakes ok when cold but banged like hell when hot. Checked pistons found one would push out but refused to retract even under drastic persuasion. Replaced caliper but kept the discs and pads and all ok now. One upside is that car is much quicker now. Must have been getting sticky for some time.

Good luck :)

cheers lads, have it booked in for next week, my mechanic says sticky calipers are quite common & by the sounds of it this is my problem so hopefully will be sorted soon.

I had this problem on a set of used grooved disks i had, fine when cold but when hot sounded like wheels were going to fall off.
I swapped the disks over from one side to other and problem solved.
just an idea for you.

Cheers but I tried that already, the info with the discs did say that fitting the grooves in one direction might cause more vibration so I swapped them just to make sure, still the same though.

Had the same thing with ds2500 pads myself. Got too hot and left pad deposits on the discs which made them vibrate like mad. Couldn't get rid of the deposits ( short of skimming the discs) so stuck some new ones on. I stopped using those pads since.

i have this when braking say from between 60 down to 40???? i know that when i changed the discs and pads the passenger size inside piston was an absolute pig to get back in. would this be my problem too?
how do you rectify a sticky piston?

The pistons should push back relatively easily (fair pressure required but not excessive).

I guess it could be an issue.

I had the same experience with these pads on a brembo set up (330mm discs). As soon as it started to vibrate, I eased off the pedal slightly, re applied and all was well again. Weird.

Well it wasn't the pistons sticking. Mechanic checked the car yesterday, the discs (supposedly uprated discs) were giving up at 200degrees, not worth the metal used to make them. Was speaking to the retailer & he has taken them off the shelve, couldn't believe how poor they were. He's replacing the discs free of charge, hopefully the new ones will be better.

How do you mean 'giving up at 200 degrees'?

Do you mean warping?

Im also suffering from this at the moment, just got the godspeed 335 kit with ds2500 pads and after 20 miles I noticed a knocking noise from the passenger side, its like a loose bottle in the car ie a knock when I accelerate and when I brake, and also vibrating when braking from 60+, anyone else experience this? :confused:

Hi Tim
Check your wheel balance weights are not knocking on the calipers , sounds like that to me.

When you fitted the discs , did you clean the drive flange face up so the disc sits perfectly , any much on there and the disc wont run true.
Also check that the pads went in easily , if there is brake dust / rust inside the calipers , and the pads are a tight fit going in then they cannot move off the discs as they should and could overheat and cause pad deposits

Let me know

Chers Ian

Yeah brakes are fine at low temps but were warping at higher temps, just cheap quality I reckon.

Once warped, they're warped. You will feel that the disc has become 'wavey' in shape at any speed once they've failed like this.

I suspect a different problem other than discs to be honest.