First time poster…long time lurker! I think I finally have an issue, that I haven’t found the answer for (though I’m happy to be corrected). I’m hoping someone has experience of this issue.
I changed the front brake pads on my Mini One D 2011 (R56).
Since the change the brakes have been alot spongier than previous times I have changed break pads. I did not change the discs and so I out it down to this.
Looking at the discs after driving today though, it is clear the pads aren’t making contact with the outer 2 inches of disc. This is on both front wheels.
The new pads are identical to the old ones, and so I know that isn’t the issue.
Any ideas would be very welcome.
The pads are making full contact with the rotor.
But the rotor is pitted with rust.
This is different though…the picture from the OP just looks like surface rust, not pitting.
Is the same thing happening on the other side?
It’s almost like the brake pad is jammed in the caliper or something, and not making full contact with the rotor.
Blowing up the picture to full size does make it appear (to me) that the rust is in deep pits.
Looks like surface rust to me, not deep pits.
Since the OP didn’t change or machine the rotor, I am going to suggest the rotor has a bit of taper wear in the surface… thinner on the outer than the inner and the pad is not yet worn in enough to make full contact. This would leave the rust and make the pedal spongier. I’d say it needs more break-in miles.
You need to have a flat surface on the rotors to match the flat surface on the new brake pads. Your brake rotors are probably worn and rusted to the point that they are not serviceable and need to be replaced.
Thanks for all the replies.
It’s just surface rust, I can wipe off with my finger. The day before I changed the pads it was all clean.
This could definitely be it. I didn’t notice a gradient on the old pads. However, it could be I missed noticing it because I wasn’t looking for it.
It’s the same on both front wheels, I’ll have a check and send more photo’s tomorrow for the inside of the disc, to see if there’s a difference with that.
Get new disks before you wear the Irregular disk pattern into the pads. I always replace the disks when I replace the pads to make sure both surfaces are flat and they make full contact. Unless it’s an exotic car, the disks aren’t expensive. I don’t consider a Mini exotic, even if it’s a BMW.
That is a floating caliper and it looks like the caliper isn’t floating like it should. My first instict is that if this started immediately after the pad change, then either a caliper bracket mounting bolt(s) are loose or the bolts for the caliper are over torqued.
If you did not replace the brake caliper hardware (the SS metal parts at either end of the pads), this could also cause this.
What I am seeing is that when the brakes are applied, the outside of the caliper is pulled in, but in your case, it is not being pulled in evenly. The bottom is being pulled in and the whole caliper is going cockeyed when the pressure is applied.
If there genuine BMW brake pads there handed- left/right and also inner/outer they can do this if there fitted wrongly
It looks to me like the pads aren’t making proper contact to the rotors. The rotor could be sticking or the pads aren’t sliding properly.
Once the pads brakes are properly working - the rust will be gone the first time you brake.
Looks like I’ve found the issue. The new brake pads had pins on the surface which were in a different position to the originals. When braking the calipers were forcing the pad closest to the centre in further than the outside.
The inside pad was fully engaged with the disc.
Thanks for all of your help and suggestions.
So can you translate that into plain english, please . . . ?!
You bought the wrong brake pads . . . as in for a different application, different trim level, different model, different, year or something along those lines?
The brake pads you bought were junk, because they just plain don’t fit correctly?
There are a few brands of brakes that I really don’t want to deal with, because they consistently don’t fit the application correctly.
Since you weren’t entirely clear on what brand brake pads you installed . . . unless I missed something . . . I’m assuming the ones that didn’t fit were aftermarket. If so, were they house brand brake pads? I’ve seen the most problems in that particular category, as far as aftermarket brake pads go
An additional thought just occured to me . . . is it possible you reversed the inside and outside pads? Depending on the design, this may be possible, with some consequences
Thanks for that information
This was the very first review in that link . . .
“checking with the product code and with the store checking against stock they had, we had to grind off the location lugs as they interfered with it seating correctly.”
That pretty much sums it up . . . in my opinion, any brake pads that have to be modified to fit are