The reason why I had to change my front discs, take a look!

**v6vc** · 23rd June 2010, 08:54

The pictures are of both the front discs, piston side ....

I've never seen anything like that, anyone have any ideas what would have caused the problem? There's a groove and also the surface is obviously screwed!

I was expecting the pad to be destroyed but the only problem with it was where it had sat against the groove on the disc!

**Duncan** · 23rd June 2010, 09:11

Yikes!!!

Have your pads been constantly rubbing on that side? Piston not retracting fully? and therefore constant heat build up, wrecking the surface. If it was I'd have thought you'd have felt them binding/dragging at times.

**danBoy** · 23rd June 2010, 09:16

Oooh not good, I can see why you needed to change them now.

**Ian-Highlander** · 23rd June 2010, 09:18

Definitely looks like it's been rubbing constantly. I'd make sure the piston isn't seized or too stiff if I was you so it doesn't do it to the new ones too.

**parsco** · 23rd June 2010, 09:19

Ahh that's nothing, they've got a few 1000 miles left in them yet

I've managed to take mine down to make the edge as sharp as a knife

(that was bad) lol

**v6vc** · 23rd June 2010, 09:24

Originally Posted by Duncan

Have your pads been constantly rubbing on that side? Piston not retracting fully? and therefore constant heat build up, wrecking the surface. If it was I'd have thought you'd have felt them binding/dragging at times.

This is what I thought initially but then thought again because;

A, The pad was no more worn on that side than the other side of the same disc.

B, The pad was in surprisingly good condition considering the disc surface

C, It didn't pull to one side at all

D, The piston pushed back in quite easily when changing the pads.

The only thing I noticed was a bad steering wheel wobble from braking at about 60mph. The brakes were still effective and I just put it down to a lost wheel weight or something!

I do wonder if that caliper is playing up. When I changed the pads and discs and pumped the pedal a bit to get pressure, that wheel, spun (by hand) much more freely than the other .....

**Duncan** · 23rd June 2010, 10:16

Originally Posted by V6VC

The only thing I noticed was a bad steering wheel wobble from braking at about 60mph. The brakes were still effective and I just put it down to a lost wheel weight or something!

Sounds like warped discs then. Wobble at 60mph without braking would be wheel balance, wobble whilst braking will be warped discs. That would then cause them to constantly touch on and off the pads and build up that heat.

**fastcarmanaic** · 23rd June 2010, 10:18

was the pad worn flat, or did it have a weird angle on the edge?

On the one picture it looks like only a section of the pad was touching at times, could be the piston was twisting in the caliper????

**v6vc** · 23rd June 2010, 11:34

Originally Posted by Duncan

Sounds like warped discs then. Wobble at 60mph without braking would be wheel balance, wobble whilst braking will be warped discs. That would then cause them to constantly touch on and off the pads and build up that heat.

Hmmm, a warped disc is something I didn't think of! May well be the answer

**v6vc** · 23rd June 2010, 11:38

Originally Posted by fastcarmanaic

was the pad worn flat, or did it have a weird angle on the edge?

On the one picture it looks like only a section of the pad was touching at times, could be the piston was twisting in the caliper????

Hi mate

Nope. There was no real difference between the thickness of all 4 pads and the only odd wear on that particular pad is where the groove is. I would have expected the pad to be destroyed after touching that surface!

The piston twisting, hmmm, what's the thinking behind that?