original_ian

I have a set of 355mm Red AP Racing 6 pot callipers with Ferodo DS pads. They have been on the car since November last year (4 months at the time of writing)…. And they have just started to judder when braking gently from about 70 mph.

They have only done about 2500 miles!!

Any one else had the same problem? Where do you reckon I stand with the warranty… is there one? They were purchased from Godspeed and fitted by the previous owner. I have the invoice.

The car is used as a daily driver with no track day action or heroics. I would have expected more from such expensive and allegedly top notch brakes!

Luminous

iTrader: (3)

Could be wheel balancing. I was getting judder from my car at 70mph (MY99 UK Turbo, std brakes). The judder was quite pronounced and uncomfortable.

Recently I got a new set of wheels, and 95% of the judder has gone. I guess the issue was balancing, and the new wheels are not totally perfectly balanced just yet either.

jasonius

iTrader: (1)

could be pad deposits/transfer, can you see any 'shadow' like patches on surface of discs..?

Like this:

http://i14.photobucket.com/albums/a3...1298Medium.jpg

bighead

iTrader: (1)

my AP 6pots have no probs at all..........maybe you have warped the disc ?
ps they are top notch

MaDaSS

I would, based on your initial post, also agree with jasonius here and say it is probably pad deposits.

p1doc

pad deposits from lack of use likely do several high speed to zero stops and this should clear it
martin

jasonius

iTrader: (1)

Is this usually the case with performance brakes, that they need to be driven hard or you risk them 'going off'..?

See here for info on pad deposits and how to get rid of them, note on the technique, don't come to a complete stop during the series of hard brakes..! Slow to around 10mph then build speed back up (ideally without braking again until the higher speed is reaches). Coming to a complete stop with hot pads can cause problems with heat transferring into on place on the disc..!

StopTech : Balanced Brake Upgrades

dynamix

iTrader: (3)

You wont clear it with the DS2500 if it is pad deposits as it is these pads that have caused the problems in the first place. Get some proper pads in there to scour the surface but once it starts going like this I would say get them skimmed or take them back.

Hoppy

DS2500 are undoubtedly good pads, but I've also had pad deposits on my AP discs using them, which I couldn't get rid of. But the discs were just about shot anyway, so I fitted new with Pagid RS421 pads. No probs now

First thing I would do is get the wheels carefully balanced, and while they're off, take a good close look at the discs with their senior technician. There might be a cheap and easy solution

Richard.

PS Out of interest, are these AP discs or Godspeed's own? Not that it makes much difference, I guess

PPS That StopTech link is often quoted as evidence that warped discs don't exist. They do, but StopTech call it 'coning' and two piece discs (separate bells, as you should have) are pretty much immune to this.

original_ian

Thanks all for your replies.

I spoke to Ian from Godspeed today (they are the AP racing ones, not his own) – extremely helpful chap. I have 12 months warranty on them that covers all sorts so there is no rush.

He says to take them off and clean up the mating surfaces to check if any rust or what not has built up between the bells and the hubs… If I can establish that isn’t the cause he’ll replace / repair no questions asked.

Can’t say fairer than that.

It’s due in for a service in 4 weeks. I’ll have them removed & cleaned up then. I’ll report back here fyi.

In the mean time I’ll go for a rip on my next long journey and do as jasonius suggests. Any excuse hey? If it works I’ll let you guys know.

Jasonius: No, they look like new (as you would expect) – lovely and shiny.

Luminous

iTrader: (3)

If you are getting any vibration through the steering wheel on a steady throttle at higher speeds also check that your wheels are well balanced.

warrenm2

most likely need a few hard stops from high speed, another thing to consider is wheel bearings

dynamix

iTrader: (3)

that will just make it worse IMO

Fizz

iTrader: (1)

I would suspect a wheel balanceing or buckled wheel first... I had a slight buckle in one and the judder was bad through the wheel.. had new wheels and it's fine now!!