Odd brake pad wear

Started by Padge, January 9, 2023, 14:28

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Padge

Afternoon all,

Wondering if anyone has seen this before/got any ideas please. EBC Yellowstuff pads which have been used on track. On both sides at the rear, the outboard pad is sitting slightly proud of the disk, and has worn a large lip which has in turn caused that pad to not make full contact with the disk (you can just about see in pictures a rust ring on the disk). The inboard pad on both sides is perfectly fine.

I didn't notice it sitting proud of the disk when installing but probably didn't even look. When replacing the pads I also replaced the hardware/shims that sit in the carrier.

Is this an installation error (if so what?) or a manufacturing defect with the pads?






Alex Knight

Have you checked your calipers to see if they are sticking?

Padge

They didn't seem to be sticking no, but I wouldn't have thought the calipers are even in play here are they? Even with the calipers off the pad is sitting above the disk

Carolyn

The pads are too big or the discs are too small.
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JB21

Maybe front discs on the rear (fronts are slightly smaller)

Joesson

#5
EBC Yellowstuff pads are often mentioned on here. I recall only comments concerning wear rates, not dimensional inaccuracies.
That the inner pad is within the circumference of the disc suggests that there is some misalignment with the installation of the outer pad.
You mention replacing the hardware/ shims, perhaps that is the cause of the concern as the shims are not unlike those puzzles sometimes seen in Christmas crackers and it would not be too difficult to get them not quite right.
I suggest that you file the lip off the pad/s, also use the file, gently, on the location groove at the ends of the pad to ensure the pad is sitting correctly in the caliper. Check the installation / arrangement of the shims with the knowledge that the pad has been too high previously.
PS just seen @Carolyn 'S comment about relative size of the disc/ pad and that certainly could be the case! My comments may apply but only if the pad/ disc sizes are correct.But, My pads are inside the disc circumference!

PS
Reference to comment concerning disc dimensions and with ref. to  Europarts Eicher discs,
Rear Disc 263mm diameter x 15mm thick.
Front disc 255mm diameter x 18mm thick.
Something quick and easy to check.

threepot

Show us the surface of the discs! Good in focus pictures.

It looks like the pad is wearing faster on the outer edge than the inner, causing it to lean over.

Maybe the outer edge of the disc is corroded or cracked etc?

Padge

Apologies my phone camera isn't the best, here's some pics of the disc

Looks like the difference between front and rear discs is 6mm - the lip on the pad is tiny, far smaller than 6mm so doubt that would be it, also because the inboard pad is perfectly fine.

From Joesson's post I am going to double check the hardware in a bit, I'm wondering if the "spring" for the outboard pad is pushing the wrong way (ie towards edge of disc rather than centre) I'll update when I go nad have a look.







threepot

That disk is f***ed and will destroy any new pad you put at them.

MRSwede

Should the pad wear indicator plate not be on the inside ? And its a little bit hard to see, aren't the support plates mounted upside down (wrong way around)

Padge

#10
Quote from: threepot on January  9, 2023, 18:02That disk is f***ed and will destroy any new pad you put at them.

How so? What looks on the picture like cracks/pitting is just from a splash of isopropyl. I've not measured them but wondering what makes you so sure

Quote from: MRSwede on January  9, 2023, 20:42Should the pad wear indicator plate not be on the inside ? And its a little bit hard to see, aren't the support plates mounted upside down (wrong way around)

Usually yes but the in and outboard pads have different "ears" on them and can't go on any other way so the wear indicator has to go that side. RE the support plates yes good spot I believe that is the issue, haven't had chance go out again as of yet

MRSwede

Meaning that the indicator should be mounted on the inside pointing down.

threepot

Quote from: Padge on January  9, 2023, 21:10How so? What looks on the picture like cracks/pitting is just from a splash of isopropyl. I've not measured them but wondering what makes you so sure

Because the surface on the outer inch of the disc is no longer a ground polished surface.

That shitty surface will just abrade the pad away on that contact patch, then you are back to braking only on the polished part, and your pad will be squishing wonky again.

They are buttons to replace, far less valuable than your time, or the yellow pads!

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Padge

Do you replace your discs after the cars been sat for a couple weeks and they get rusty then too?

I'll definitely keep an eye on it and appreciate the response but I think replacing the disc just because of that is a little premature

Padge

Quote from: Padge on January  9, 2023, 23:45Do you replace your discs after the cars been sat for a couple weeks in the rain and they get rusty?

I'll definitely keep an eye on it and appreciate the response but I think replacing the disc just because of that is a little premature

Gaz mr-s

Quote from: threepot on January  9, 2023, 18:02That disk is f***ed and will destroy any new pad you put at them.

+1

That's too far gone.

JB21

Quote from: Padge on January  9, 2023, 23:45Do you replace your discs after the cars been sat for a couple weeks and they get rusty then too?

I'll definitely keep an eye on it and appreciate the response but I think replacing the disc just because of that is a little premature

If the disc has any sort of lips on the rusted outer parts then the new pads will just contact on these outers rusted parts of the discs, therefore ruining your new pads. If the disc has no lips then just use a wire brush attachment on a drill and bring them back to polished metal and you'll be fine.

Padge

To update, the pad issue was indeed the shim/hardware in the carrier being the wrong way round

Been for a test drive and discs are nice and shiny throughout, no lips. Appreciate the concern though

Joesson

Quote from: Padge on January 10, 2023, 13:17To update, the pad issue was indeed the shim/hardware in the carrier being the wrong way round

Been for a test drive and discs are nice and shiny throughout, no lips. Appreciate the concern though

Solution suggested post #5 in 1 hour 20 minutes.
Must be quicker than waiting for an ambulance!

threepot

Sounds promising, I guess 1000 miles or another good track day will show you the real proof of the pudding. Good luck and enjoy. :)