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Weirdly then every single car I’ve ever owned has had this design and none have had this issue unless there was an issue with the sliding pins.


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Even more weirdly then every Jag I have ever owned has had this issue and I have never had sticking caliper pin(s).
The plot thickens!
 

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Weirdly then every single car I’ve ever owned has had this design and none have had this issue unless there was an issue with the sliding pins.
Same here Chris, always used Pagid pads actually.
 

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I don't have brake judder at all. I have mintex discs and pads on rear, QH on front , no idea what pads are on the front but they were the wrong ones. As they were almost new when I got the car I decided to machine them up to the correct shape. Out of interest I always file or machine the new pads to round off the sharp corners and file up and repaint the carriers, once again making sure there are no sharp edges. When I change pads I always spin up the discs on my lathe, unless they are close to minimum thickness when I replace them.
 

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Discussion Starter · #45 · (Edited)
I don't have brake judder at all. I have mintex discs and pads on rear, QH on front , no idea what pads are on the front but they were the wrong ones. As they were almost new when I got the car I decided to machine them up to the correct shape. Out of interest I always file or machine the new pads to round off the sharp corners and file up and repaint the carriers, once again making sure there are no sharp edges. When I change pads I always spin up the discs on my lathe, unless they are close to minimum thickness when I replace them.
I wish I had a lathe Fred. I only have a milling CNC that although its working area can fit the brake disc, I am not sure if I can align the top and bottom surfaces properly. It’s made for wood and soft metals. The resolution is 0.025mm
 

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Even more weirdly then every Jag I have ever owned has had this issue and I have never had sticking caliper pin(s).
The plot thickens!
I didn’t have my diesel long enough to change the pads but I’m glad there are a few of us with this ‘problem’ and it’s not just me. There is definitely some sort of issue with my wear pattern though, pads aren’t sitting right on the inside.
 

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Here’s a novel thought.

The rear pads on eldests Mini are handed for the wear sensor.

We got that terribly wrong the first time we changed then an had two outer pads on the rear passenger side. Two inners on the drivers side.
The wear on the passenger side was horrendous on the inner pad because it couldn’t move in the carrier.

Once corrected with new pads and discs (an expensive schoolboy error) all was grand.

I wonder if that’s the answer?
 

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Discussion Starter · #48 ·
I changed the rear ones on my Toyota for exactly same reason. When I did it 4year ago. I put normal grease. The rubber swallowed almost to double its normal size. Slider pin was seized very badly. I had to damage it and replace it. Now it moves freely but it wobbles like 1mm. Before I though it shouldn’t and it seized up. The pins on XF do move but not as freely as I think they should. They fill like to be on correct tolerances but I think it should be a bit looser. It’s the pd that align everything not the rubber standing all that force. Add thermal expansion to that, It’s certainly worse than when I assembled it while cold. I am going to loosen the rubber considerably see what happens. The minimum would be less vibration will be transferred to steering system.
 

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I wish I had a lathe Franck. I only have a milling CNC that although its working area can fit the brake disc, I am not sure if I can align the top and bottom surfaces properly. It’s made for wood and soft metals. The resolution is 0.025mm
I wish I had a lathe Franck. I only have a milling CNC that although its working area can fit the brake disc, I am not sure if I can align the top and bottom surfaces properly. It’s made for wood and soft metals. The resolution is 0.025mm
If you try to machine up discs Hamed you need a lathe that is very accurate and very solid. Small cheap lathes are not big enough to take the disc and not built to the standard required. I have a colchester master lathe with a gap bed, this will take the disc and is very accurate, it takes ages to set the thing up in the lathe with dial gauges before taking a cut. I also have a Fritz Werner milling machine which weighs just under 2 tonnes which could do it with my rotary table. That is accurate to 1 10.000 th of an inch, but I use the lathe. Usually you have a step in the disc at the outer edge which can be taken off easily without being too accurate as the new pad will not be there. I always machine the pads to keep that to a few thou, this avoids the step forming in the first place, I have found over the years most pads are made to a poor tolerance stamped out roughly on a press with sharp edges and any old tolerance. May be because I always re machine them is why I don't get the judder or it may be luck.
Fred
 

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I have stock discs and pads up front. On general driving and light spirited driving it does not judder at all. However, on the track type driving 🤔 as soon as any serious heat builds up they judder. As soon as they cool down we are back to normal.

I have some MTEC slotted discs and red stuff pads sitting around to fit when I can be bothered. As it only presents itself in more extreme circumstances my motivation is low.

On the subject of Red stuff pads, EBC told me that they do not recommend the hard stops bed in method as this wears the bedding coating on the pads far to quickly. The recommended procedure is actually to do upto 500 miles of normal driving type braking.
 

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I found RedStuff terrible on the track. Fade far too quickly.


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Interesting pro cut lathe cuts down bedding in my upto 75%, never considered that on new discs.
Well, it took me about 1000 miles to bed in new discs and pads.

After pro cut lathe, it has taken 500 miles so far, and still not bedded in yet. The fronts are pretty much there, but the rears need more miles.

So read into the 75% what you will.
 

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Discussion Starter · #55 ·
I have stock discs and pads up front. On general driving and light spirited driving it does not judder at all. However, on the track type driving 🤔 as soon as any serious heat builds up they judder. As soon as they cool down we are back to normal.

I have some MTEC slotted discs and red stuff pads sitting around to fit when I can be bothered. As it only presents itself in more extreme circumstances my motivation is low.

On the subject of Red stuff pads, EBC told me that they do not recommend the hard stops bed in method as this wears the bedding coating on the pads far to quickly. The recommended procedure is actually to do upto 500 miles of normal driving type braking.
This is interesting an matches my idea. Maybe slider pins move more difficult when get hot.
 

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Discussion Starter · #56 ·
If you try to machine up discs Hamed you need a lathe that is very accurate and very solid. Small cheap lathes are not big enough to take the disc and not built to the standard required. I have a colchester master lathe with a gap bed, this will take the disc and is very accurate, it takes ages to set the thing up in the lathe with dial gauges before taking a cut. I also have a Fritz Werner milling machine which weighs just under 2 tonnes which could do it with my rotary table. That is accurate to 1 10.000 th of an inch, but I use the lathe. Usually you have a step in the disc at the outer edge which can be taken off easily without being too accurate as the new pad will not be there. I always machine the pads to keep that to a few thou, this avoids the step forming in the first place, I have found over the years most pads are made to a poor tolerance stamped out roughly on a press with sharp edges and any old tolerance. May be because I always re machine them is why I don't get the judder or it may be luck.
Fred
You have everything needed to build the car Fred, let alone the brakes!
 

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This is interesting an matches my idea. Maybe slider pins move more difficult when get hot.
Yes, on the rears when fitted the mtec discs and redstuff pads I cleaned everything really well using wire brush attachments on my dremel as some areas are hard to get at. I replaced the slider rubber boots and there was a lot of corrosion in this recess you would not even notice if the rubber boot was not removed or replaced. The dremel made short work of the corrosion and I coated it in some o ring grease to help with this issue.

I think that when this corrosion builds up and the area gets heat it squeezes the rubber boot and in turn this creates friction on the slider pin. This friction stops the caliper sliding back appropriately, this then cause deposits to based on the discs.
 

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Discussion Starter · #58 ·
Yes, on the rears when fitted the mtec discs and redstuff pads I cleaned everything really well using wire brush attachments on my dremel as some areas are hard to get at. I replaced the slider rubber boots and there was a lot of corrosion in this recess you would not even notice if the rubber boot was not removed or replaced. The dremel made short work of the corrosion and I coated it in some o ring grease to help with this issue.

I think that when this corrosion builds up and the area gets heat it squeezes the rubber boot and in turn this creates friction on the slider pin. This friction stops the caliper sliding back appropriately, this then cause deposits to based on the discs.
Totally agree. I noticed judder is worse when exiting a long motorway drive which I think will create some heat. I will use a heat gun to warm slider and see if I can replicate it. The I will try to increase ID of the rubber using a file see what happens.
Probably cars with bad bearing will have a hotter hub and suffer more.
 

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Could the mating surface between the disc and the hub cause judder if there's crap/corrosion there?
 

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Discussion Starter · #60 ·
Could the mating surface between the disc and the hub cause judder if there's crap/corrosion there?
Yes that’s one of the main reasons. Assumption is everyone cleans it properly before putting on the new rotor.
 
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