Horrible Brake Judder when EBCs are hot. Any ideas why?

[Ej1749]

Trying to get smooth brakes when hot? Any help would be great. Sorry for the long story, just a bit bored and wanted to be specific.

I was hammering the crap out of an Aston Martin DB11 the other day and the brakes as standard are pretty good, they do fade quite quickly though understandably with the power and weight of the car. However, I had a bit of a (heart falling out my arse moment) when I came off the motorway and pressed the brake pedal and nothing happened whilst approaching a round about in a £170K car that isn't mine haha (I think most of us have had that "brakes are on lunch, be back soon" feeling before:grin:)... just managed to stop in time at the red light (no one else around btw, was being as safe as possible with great visibility). However, the brakes were cooked as I had been giving it a beating for a good half an hour.

The reason why I mention the above about the Aston and how it relates to my Golf. When the brakes were fading and running out of puff, they were still extremely silky, silky, silky smooth even when they were catching fire and glowing red, ZERO horrible brake judder. Now I know Aston Martin's are going to be extremely refined compared to a Golf, but I have EBC grooved discs and Red stuff pads which are probably as good as, if not better than the Aston's standard performance steels.

I have followed the exact EBC bedding in procedure but I still get huge amounts of brake judder after say 5 reasonably hard slow downs on the motorway, say 60 seconds between each slowdown/brake to cool them a tad. The stopping power is unreal when they are hot, but the brake judder is horrendous, so bad it feels like the callipers are not attached, similar to snapping a drive shaft or broken diff, but worse. Then when they're cool, they don't judder as much but do feel a bit grindy which I expect from a performance pad.

I want to see if it's possible to get the brakes to be smooth constantly especially when they are fading and hot, as I do want to take it on track this year, but I can't, as it'll rattle my teeth out unless I get it sorted.

Things that maybe causing this - I have spacers on the car and there is a bit of rust between the spacer and the hub. I have tried to clean it, but I'm wondering if this could be a contributing factor. My H&R lowering springs are slightly un-even, one side is about 5mm lower than the other. Importantly, there is a scary dead spot when normal town driving at the top of the brakes and you have to push quite hard and the pedal quite far to get any sort of bite. So my master cylinder could be on it's way out. I have bled the brakes and this made the cold bite better for a bit, but now the cold bite is bad again. The cold bite feels similar to hot brake fade, unless you press really hard then it gradually bites hard, just like hot fading brakes, but they are cold. I get these aren't great when cold, but this is defo not right.

The EBC and red Stuff are crazy powerful and get better the more miles I put on them, but the judder is horrendous when they are hot and the bite when they are cold is dangerous tbh and I am expecting a baby any time now and need perfect brakes. Does anyone have any ideas or recommendation's for the cold bite being crap and the brake judder when hot?  Any brake specialist garages around that I could visit?

[azcs]

Hi Mate,

Have just had ebc yellows fitted about 400 miles ago so still bedding them in properly really. But have noticed a similar lack of bite at the top of the peddle. Would be interesting to see other peoples experience with this. As you say only really matters when driving around town and you want some instant bite.

[rajb]

That’s a good read and interested in if the half hour DB11 session is open to anyone LOL.

Anyway, your brakes. So I think I mentioned in your other thread that I personally don’t like EBC as I’ve had issues many many years ago.
Juddering when warm/hot is due to the expansion of the disc being uneven and can be noticeable even when cold but only very slight. When I had this a couple of times previously, once I replaced the discs and that sorted it and the other I had the disc skimmed on the hub to sort the runout and get them to run true to the hub.

[Ej1749]

Yes, I expect a little less bite than standard being performance pads as they are cold, but this is potentially dangerous. I'm not fussed about myself but if my partner ever drives the car with the baby in it, that is when I would be worried ha. I know Lamborghini Aventadors used to have the same problem when they came out and as far as I remember they recalled all their cars to amend this, I wondered what they did hmmmm? and how much that cost Lambo's bank account haha!

Hi Mate,

Have just had ebc yellows fitted about 400 miles ago so still bedding them in properly really. But have noticed a similar lack of bite at the top of the peddle. Would be interesting to see other peoples experience with this. As you say only really matters when driving around town and you want some instant bite.

[Ej1749]

If I'm ever about I'll see if I can let you have a blast in it Haha! if I'm being honest it my pops car, but don't ever want come off as if I'm boasting as that's sh!tty! So, I just say I was driving someone else's car haha The balance and feel of those cars in the corners are amazing. I have driven other peoples cars over the years like Ferrari's, GTR's, Porsches, Bentleys super sport new shape R8's etc, (Those cars were genuinely other peoples ha) and the only thing that comes close to feeling as good as an Aston in the corners is a Porsche. Porsche's are the "sleeper" of sport/super cars and the Turbos S when it launches literally rotates the earth below it, slowing down time!

Anyways, yeah I have heard that the heat could have caused the disc to be uneven. If you have them skimmed again apparently you need brand new pads or it can repeat itself and become uneven? Did you get new pads after you had them skimmed?

Also, skimmed on the hub is not something I have heard of before, but I think I have seen a video of this being done. Do you recommend anywhere to get them skimmed to the hub? Will this mean I need new pads after? Also, did it make a big difference to the judder?

And finally, what brakes do you run now and would you recommend them?

That’s a good read and interested in if the half hour DB11 session is open to anyone LOL.

Anyway, your brakes. So I think I mentioned in your other thread that I personally don’t like EBC as I’ve had issues many many years ago.
Juddering when warm/hot is due to the expansion of the disc being uneven and can be noticeable even when cold but only very slight. When I had this a couple of times previously, once I replaced the discs and that sorted it and the other I had the disc skimmed on the hub to sort the runout and get them to run true to the hub.

[SRGTD]

I had a similar brake judder issue many years ago on a Ford - the steering wheel vibrated really badly when braking. The front discs were replaced under warranty, only for the same problem to happen again a few months later with the replacement discs. I can’t remember if the pads were also replaced as I’m going back to the early 1980’s.

I’m not hard on my brakes and I’d owned the car from new so knew how it’d been driven, so the discs hadn’t warped as a result of excessive heat build up. It turned out the original discs and the replacements were from a faulty batch.

[Ej1749]

I wonder if EBC will accept a warranty claim as mine are only a several weeks old and have done about 1500 miles, with the exact bedding in process they require. I'll have to give them a shout. Thanks

I had a similar brake judder issue many years ago on a Ford - the steering wheel vibrated really badly when braking. The front discs were replaced under warranty, only for the same problem to happen again a few months later with the replacement discs. I can’t remember if the pads were also replaced as I’m going back to the early 1980’s.

I’m not hard on my brakes and I’d owned the car from new so knew how it’d been driven, so the discs hadn’t warped as a result of excessive heat build up. It turned out the original discs and the replacements were from a faulty batch.

[rajb]

Anyways, yeah I have heard that the heat could have caused the disc to be uneven. If you have them skimmed again apparently you need brand new pads or it can repeat itself and become uneven? Did you get new pads after you had them skimmed?

Also, skimmed on the hub is not something I have heard of before, but I think I have seen a video of this being done. Do you recommend anywhere to get them skimmed to the hub? Will this mean I need new pads after? Also, did it make a big difference to the judder?

And finally, what brakes do you run now and would you recommend them?

So the ones I had skimmed on the hub were on my X5 as they were my BBK discs and couldn't justify a new set of discs at the price they cost lol. The disc skim was about £60 per disc but in that they removed the disc to completely clean the hub face to remove as much build up to ensure a good mating surface. The place I used was in Birmingham so depends where abouts you are but they have places all over the UK that use the procut machines (https://skimmydiscs.co.uk).

With this you don't need to replace pads as I didn't.

Once skimmed the judder was gone and didn't return even after some heavy braking. Obviously that doesn't mean it would be the same for every application as I guess different discs can react in different ways but I've had it done twice and both times were all good.

So currently on there X5 I'm using Brembo Discs/Pads, my 335i is running Alcons using Alcons discs and DS2500 pads and the GTI is using Ate pads with the grooved discs (unsure of brand) that came with the TTS brakes I swapped from the other GTI I bought. The GTI setup at the mo is superb and I can hammer them with no issues.

Have run Pagid RS29 pads which are superb too.

[Ej1749]

I appreciate the response on this. I will definitely have to have a look at the ATE and Pagid pads.

At one point in my life I owned a new shape Astra VXR... Yep, I was young and everyone makes mistakes haha. They had Brembo's on them. They were great, but didn't last more than 4000 miles as the pad was so soft. I also went to replace all the discs and pads...... £3150.00.... I nearly cried, as you could not get them anywhere other than Vauxhall as the car was so new. I had to sell the car because at the time I could not afford that. Even now I would have to save up for that. But I might give the pads a try though in the Golf.

Maybe I got the discs too hot during the bedding in process haha.

Anyways, yeah I have heard that the heat could have caused the disc to be uneven. If you have them skimmed again apparently you need brand new pads or it can repeat itself and become uneven? Did you get new pads after you had them skimmed?

Also, skimmed on the hub is not something I have heard of before, but I think I have seen a video of this being done. Do you recommend anywhere to get them skimmed to the hub? Will this mean I need new pads after? Also, did it make a big difference to the judder?

And finally, what brakes do you run now and would you recommend them?

So the ones I had skimmed on the hub were on my X5 as they were my BBK discs and couldn't justify a new set of discs at the price they cost lol. The disc skim was about £60 per disc but in that they removed the disc to completely clean the hub face to remove as much build up to ensure a good mating surface. The place I used was in Birmingham so depends where abouts you are but they have places all over the UK that use the procut machines (https://skimmydiscs.co.uk).

With this you don't need to replace pads as I didn't.

Once skimmed the judder was gone and didn't return even after some heavy braking. Obviously that doesn't mean it would be the same for every application as I guess different discs can react in different ways but I've had it done twice and both times were all good.

So currently on there X5 I'm using Brembo Discs/Pads, my 335i is running Alcons using Alcons discs and DS2500 pads and the GTI is using Ate pads with the grooved discs (unsure of brand) that came with the TTS brakes I swapped from the other GTI I bought. The GTI setup at the mo is superb and I can hammer them with no issues.

Have run Pagid RS29 pads which are superb too.