SpeedyC2

Is it common to reqiure some filing or grinding of the backing plate on the brake pads?

In trying to change the pads last night (for the first time since I've owned the car), it became obvious the new pads were too wide - the backing plate extending to the sides beyond the pad material will need to be removed. I have an S2, and am using Mintex pads, and they are the correct part number.

Upon examination of the old pads, it appears they had been ground down to remove excess material from the backing plates as well. Further, I bought a set of slightly used Pagids from a Rennlister for track use (haven't used them yet), and when I checked them they had clearly been trimmed too.

So I guess this is normal? All I have right now is a hand file, and that's not gonna cut it. I'm gonna need a grinder or dremel unless I want to work on this for hours...

Dougs951

Not normal...

SpeedyC2

Yeah, it doesn't seem right.

The other issue I'm running into is the inside pistons don't want to fully retract. I'm thinking a caliper re-build is in order...

MAGK944

Definitely something wrong, those pads should drop right into the Brembos. You should not have to file anything. Are you sure they are not S or M030 pads?

Jfrahm

I often lightly dress the edges of the backing plates but have not needed to take a grinder to them. I have some new PBR pads handy, still in the wrap and the plate seems to be 97 or 98mm wide (and not very well finished on the edge.) Some Porsche stockers I also have handy are about 97.3mm wide.

Light filing on the pads is not uncommon in my experience but nothing that would take more than a minute or two. On the other hand I have also had pads that would clunk around in there due to too-narrow backing plates, perhaps 1.5mm of slop.

JustinL

I've had to grind backing plates before. Some manufacturers more than others.

SpeedyC2

I'm beggining to suspect maybe a past owner swapped calipers on the car. I am the third owner of a 23 year old car, after all. Still, I have pretty complete service records and there is no mention...

Still the calipers are Porsche Brembo, and appear to be the correct caliper, but I'm going to find the caliper part number and check.

[Update]: Checked the calipers and couldn't find a part number. All four are the same, and are stamped Brembo, so I guess there's no reason to think they aren't correct. I'm a bit baffled...

N_Halbert

I know I have to hit the plates on my pads to get them to slide in with out excessive force and so they have just a touch of slop. You don't want them handing up. I believe it has to do with the age and buildup of dust and corrosion under the spring plates. The plates are steel and the caliper body is aluminum. I use a fine pick to get under there and clean along with compressed air. Eventually I will have them rebuilt with new finish and spring plates.