Really bad brake judder
10-11-2010, 12:04 PM
#16
Nordschleife Master
Thread Starter
Hi Steve, t'was a good day yesterday, eh?
I too have developed a brake judder, though in my case it has not gone away now brake system is cooled. Towards the end of one of the last runs the brake pedal became very soft/spongy. I let it cool for a bit longer than normal but had judder in the next run, which got worse as time went on. Drove it this morning and it is quite bad even when cold.
My favourite mechanic (you know who) reckons it is warped rotors, taking it in next week to check/fix - just in time for Curborough... I'm gonna have to rethink things though - this is the second time I've damaged the brakes in only 3 trackdays! I must be a harsh braker - might go to track pads for the next one to see if it helps.
Cheers Andrew.
I too have developed a brake judder, though in my case it has not gone away now brake system is cooled. Towards the end of one of the last runs the brake pedal became very soft/spongy. I let it cool for a bit longer than normal but had judder in the next run, which got worse as time went on. Drove it this morning and it is quite bad even when cold.
My favourite mechanic (you know who) reckons it is warped rotors, taking it in next week to check/fix - just in time for Curborough... I'm gonna have to rethink things though - this is the second time I've damaged the brakes in only 3 trackdays! I must be a harsh braker - might go to track pads for the next one to see if it helps.
Cheers Andrew.
So.....we've both 'warped' our front rotors on the same trackday...you with standard pads all round and me with a mix of high temp track pagids on the front and standard on the rear. The plot thickens!
However...you've got small 2 pots on the rear, so that could mean that you were also working your front pads too hard which would be a commonality between us.
10-11-2010, 12:23 PM
#18
Rennlist Member
PAD TRANSFER! Common issue with Pagid compounds. The pagids are prone to transfer deposits onto the rotors when they get hot, every thing is fine when cool, like on the street or when you start out at the track, but as you heat them up the deposited material will caus erratic chatter and shudder that feels just like a warped disk.
This is made worse when swapping pads or putting on a new compound in an used rotor. Pagids are great pads I use them alot but the are very finicky about bedding in and the operational heat range...classic issue that will have you chasing your tail looking for a warped rotor or bent wheel or....
This is made worse when swapping pads or putting on a new compound in an used rotor. Pagids are great pads I use them alot but the are very finicky about bedding in and the operational heat range...classic issue that will have you chasing your tail looking for a warped rotor or bent wheel or....
10-11-2010, 12:32 PM
#19
Racer
Could be but when it happened to me I wasn't using Pagids as I needed to replace pads for an event and they were not available and Andrew apparently is using stock pads...
10-11-2010, 01:00 PM
#20
Nordschleife Master
Thread Starter
Donington Park. There's two very hard braking zones...I'm just about getting to 120 mph before getting on the brakes. The rest of the track only requires light braking as the corners are faster. The previous track that the judder started to show up was Silverstone which is mostly fast corners and generally regarded as 'brake friendly'.
10-11-2010, 01:02 PM
#21
Rennlist Member
It can happen with any pad, bit is very prone to disks that have run pagid compounds. It is the material that is deposited on the disk and the off gassing that is the problem. It is almost invisible if you don't know what your looking for.
10-11-2010, 01:04 PM
#22
RL Technical Advisor
PAD TRANSFER! Common issue with Pagid compounds. The pagids are prone to transfer deposits onto the rotors when they get hot, every thing is fine when cool, like on the street or when you start out at the track, but as you heat them up the deposited material will caus erratic chatter and shudder that feels just like a warped disk.
This is made worse when swapping pads or putting on a new compound in an used rotor. Pagids are great pads I use them alot but the are very finicky about bedding in and the operational heat range...classic issue that will have you chasing your tail looking for a warped rotor or bent wheel or....
This is made worse when swapping pads or putting on a new compound in an used rotor. Pagids are great pads I use them alot but the are very finicky about bedding in and the operational heat range...classic issue that will have you chasing your tail looking for a warped rotor or bent wheel or....
Some Pagids do this; others do not (such as Yellow's).
You can confirm whether they are truly warped or not by measuring their axial runout with a dial indicator.
We use Hawk Blues as an effective rotor-cleaning medium and re-bed the pads to help eliminate the problem. One must truly choose the right pad for your braking technique and peak operating temperatures.
Race pads of ANY manufacture should always be installed in all four calipers, not just the fronts as this really exacerbates the heat problem by leaving the front brakes doing the majority of the stopping efforts.
10-11-2010, 01:11 PM
#24
Nordschleife Master
Thread Starter
PAD TRANSFER! Common issue with Pagid compounds. The pagids are prone to transfer deposits onto the rotors when they get hot, every thing is fine when cool, like on the street or when you start out at the track, but as you heat them up the deposited material will caus erratic chatter and shudder that feels just like a warped disk.
This is made worse when swapping pads or putting on a new compound in an used rotor. Pagids are great pads I use them alot but the are very finicky about bedding in and the operational heat range...classic issue that will have you chasing your tail looking for a warped rotor or bent wheel or....
This is made worse when swapping pads or putting on a new compound in an used rotor. Pagids are great pads I use them alot but the are very finicky about bedding in and the operational heat range...classic issue that will have you chasing your tail looking for a warped rotor or bent wheel or....
Luckily, I can rule out bent wheels as the juddering has occurred over the two trackdays on 3 sets of wheels.
10-11-2010, 01:15 PM
#25
Nordschleife Master
10-11-2010, 01:22 PM
#26
Nordschleife Master
Thread Starter
p.s. sorry this is all getting a bit out of synch owing to replies coming thick and fast
10-11-2010, 01:37 PM
#27
Drifting
Boys.
I'm only on standard pads, with Zimmerman disks, uprated rears and no I didn't change the P/V, maybe I am lucky but I don't get brake judder what so ever, and I think I was braking reasonable hard.......
If you are going to do some swap outs to eliminate items, you've got to go back to known good, and then progress, otherwise you'll muddy the waters.
kevin
Oops, bit out of sync here too...........but as I said to Andy on the day, its always pad deposits, I've never seen a warped disk.
I'm only on standard pads, with Zimmerman disks, uprated rears and no I didn't change the P/V, maybe I am lucky but I don't get brake judder what so ever, and I think I was braking reasonable hard.......
If you are going to do some swap outs to eliminate items, you've got to go back to known good, and then progress, otherwise you'll muddy the waters.
kevin
Oops, bit out of sync here too...........but as I said to Andy on the day, its always pad deposits, I've never seen a warped disk.
Last edited by warmfuzzies; 10-11-2010 at 01:40 PM. Reason: late to the party
10-11-2010, 02:08 PM
#28
Racer
Exactly.
Some Pagids do this; others do not (such as Yellow's).
You can confirm whether they are truly warped or not by measuring their axial runout with a dial indicator.
We use Hawk Blues as an effective rotor-cleaning medium and re-bed the pads to help eliminate the problem. One must truly choose the right pad for your braking technique and peak operating temperatures.
Race pads of ANY manufacture should always be installed in all four calipers, not just the fronts as this really exacerbates the heat problem by leaving the front brakes doing the majority of the stopping efforts.
Some Pagids do this; others do not (such as Yellow's).
You can confirm whether they are truly warped or not by measuring their axial runout with a dial indicator.
We use Hawk Blues as an effective rotor-cleaning medium and re-bed the pads to help eliminate the problem. One must truly choose the right pad for your braking technique and peak operating temperatures.
Race pads of ANY manufacture should always be installed in all four calipers, not just the fronts as this really exacerbates the heat problem by leaving the front brakes doing the majority of the stopping efforts.
Good to know.
But I've only every used yellows from Pagid. Then because I needed pads fast for an event had to use EBC yellows (I'm talking f&r in both cases) don't know if these would cause it.
In any case the dial indicator did show they were warped and they were also full of cracks so I didn't mind changing them. Hope it's only pad transfer in your case.
10-11-2010, 03:32 PM
#30
Rennlist Member
I ran stock disks with pagid orange of years. Never an issue, but with bigger and bigger tires & stickier compounds there is more torque being delt with by the system. Also I found going to cross drilled disks from solid they tend to build up compound in the vent holes that then will redeposit it back on the fresh pad and then to the disk. So I'd veal a used disk carefully and the "clean" with a hawk as steve mentioned...