Db9 brake discs damaged by pads!

[craig elam]

Replaced rear pads last night with standard Pajids, when i examined the face of the old pads i noticed a several bright brass coloured spots, on the new pads theres a chamfer on each edge with the same spot.
Digging away at the old pads friction material to see what was going on, i was quite surprised to find 6 brass posts attached to the back plate.
my pads had 4mm left on them so nowhere near the sensors and these 6 "posts" were in contact with the face of the disc!!!,
so everytime you apply the brake these brass posts are forced into the face of the disc. ok brass is pretty soft compared to the steel disc but I had often wondered why there was a series of slight grooves in my discs from about 20,000 miles onwards , now i know.
I reckon these posts contact the discs at about 50% of the friction materials depth and begin to score the discs.
Another thought, the brass posts being in contact with the disc during braking must affect brake performance how can the pad friction material do its job if the disc has to wear the posts off at the same time ( i might be completely wrong about this and hope somebody comes along and puts me right).
Is this the source of THE squeek ?, I just know i dont like it and wonder how many discs have been replaced as a result. are all pads for this brembo caliper like this? might be time for a change or just replace at 50% wear.

[craig elam]

[Magic919]

You'd have thought Pagid would know what they are doing after all these years.

[craig elam]

Im sure they do!!, i just wanted to make people aware that these posts come into contact with the disc way before the warning light for thin lining comes on
and the grooves in the surface of the brake disc can be avoided by changing the pads earlier than perhaps they normally would

[8Tech]

After looking through both of your posts, I would suggest those pads have a manufacturing defect and you should contact the manufacturer reference the disc damage.

I have fitted literally thousands of brake pads over the years from standard to racing types, and that pad is just not right.

[KnowsAnAston]

This is to help bond the friction material to the backing plate of the pads. Most pads are just glued, where the friction material is glued to the backing plate using adhesive. Holes can be made in the backing plate to add to the level of adhesion and an underlayer can be used to help too
Where a pad may be highly stressed thermally, pins are used to help retain the pad material on the backing plate, despite being subjected to high shear forces.
The brass pins are softer than the friction material, and your disk, so do not cause any damage or provide a reduction in braking performance.

Any mark or grooves you have seen in your disks will be caused by the friction material and possibly road/dirt build up on the leading edge of your pad.