Motorway Speed Brake Judder?

[Euan94]

I'm getting a judder under braking but it only seems to happen at 60 or above, what would be the likely cause, warped discs?

I can emergency stop from 50 or under and don't get any judder at all yet head over 60 odd and even light applications give me a fairly bad juddering. I know the 200 brembos have issues with the pins corroding into the caliper but I'm thinking this can't be contributing here as that would surely cause problems at any speed.
Anyone had this before?

 

[Ex-User (19928)]

Warped discs can certainly cause that symptom but Im guessing there can be other causes too.

 

[JB21]

I've recently had this mate and it was warped discs (1 month old Brembo HC discs on my Mondeo ST), but it could be something as simple as pad deposits on the discs or it could also be a worn bush(s) or ball joint(s) on the front somewhere but these normally come with other symptoms such as pulling to one side, drifting around the road and/or knocks and bangs.

Best way to check if its warped discs is get a DTI (Dial Test Indicator) on the discs and if that comes back as OK try and measure the disc thickness as it could be DTV (Disc thickness variation).

Do you keep your foot on the brake when stationary by any chance? This is how I warped mine, it was caused when pushing on getting the brakes hot and then before they cooled down keeping my foot on the foot brake at lights or when stationary (I used to just do it subconsciously). You wanted to see the state of them once I took them off, you could actually feel the warping with your finger they where that bad.

 

[Knuckles]

Bed the brakes again in and see if it helps?

Are you on standard pads? I got awful judder after getting them hot once. Ended up doing away with them and I've not had brake problems since

 

[Euan94]

I did go out the other day and did some repeated heavy stops to try and get some proper heat into them but it doesn't seem to have made much difference, pad deposits was my first thought but I don't think its that anymore, and yes standard pads as far as i know.

The other thing that concerns me is that the pedal isn't particularly firm, I've got some ATE fluid now so a flush and bleed through is also on the to do list but I don't think that will contribute to this much.

@JB21 yeah i'm not particularly religious at using the handbrake so it could well be something like that

 

[JB21]

If you're local to St Helens I've got a DTI gauge you can lend.

 

[Euan94]

Unfortunately it would be a bit of a trek, cheers for the offer though!