Rear Brake pads

[JayBees7]

Can any one confirm the correct way to fit the anti rattle spring that sits inside the rear caliber and presses against the top edges of the pads. There are two small prongs on the convex face do these fit between the pads or are they locators for the calliper? Reason for asking is because the present pad set up has resulted in very excessive wear on one pad whilst seemingly no wear on the other.

[guest2360]

Normal reason for uneven pad wear is a stuck calliper.  You might also find the retaining pin is corroded.

[David.]

On a 2010 RT, the pad spring location should look like this.



The arrow faces direction of travel, the two small prongs retain the pad spring within the caliper.

From new, the two rear pads are slightly different thicknesses & do tend to wear unevenly.

"And the inside pad is thinner than the outside, so if you're watching pad thickness - always check the inside pad, it's gonna wear out first."

[Tango]

Thank you David, I was wondering why my inner pad was slightly thinner, after a quick inspection before my next trip.

[guest2360]

You said you had very excessive wear on one pad.  That is caused by the calliper not floating.  Check that it is before fitting new ones.

[David.]

I was wondering why my inner pad was slightly thinner, after a quick inspection before my next trip.

The inner pad also has wear limit holes in the back of the brake pad.

[JayBees7]

Yeah good point there the calliper floats easily and actually it is the inboard pad that has worn excessively, The pad on the piston side is like new. so I'm wondering if the anti rattle spring was fitted incorrectly and so preventing full movement on the piston side.

[JayBees7]

Thanks for that info and picture David it will be of great help when I get some new pads actually ordered from Motions. cheers

[David.]

The caliper floats easily and actually it is the inboard pad that has worn excessively.
The pad on the piston side is like new. so I'm wondering if the anti rattle spring was fitted incorrectly and so preventing full movement on the piston side.

Are the pistons free to move within the caliper, when extended, can they be pushed back flush with the caliper by hand.

[guest2360]

Heres an example of a corroded pin.  The pads were badly worn on the inside. Took some getting off.

[JayBees7]

Yes David the pistons are free I pushed them back by hand although i have to admit that the retaining pin was very dirty, I have since polished it with wire wool. Will have to wait for the new pads, believe it or not they were fitted Jan this year and only done 1900 miles.

[David.]

The caliper floats easily.

Is the pad retaining pin clean, free of corrosion & lightly lubricated.

[guest2360]

Were they genuine BMW (Brembo). Aftermarket ones can have an extremely short life as well as being fatal for the disc.