Anyone know where this little broken clip goes inside the piston? Pulled apart piston and found it broken, I guess not a spare part. Photos attached.




Regards Steve

 

Mine came out not broken - just swimming in a puddle of break fluid. I'm not a Mazda engineer, but I think the circlip goes around the threads. My intact example definitely has a slope to the circle.

The threaded rod is screwed into the part pictured, so here's my amateur guess: that circlip meshes with one of the two cutouts on the end of the female part and ensures that there's always more pressure turning clockwise than counterclockwise to keep it assembled. Placing it on that way (bent end closer to the black mechanism - I have it backwards in the picture) also makes it easier to remove, which makes sense given it just fell off in there.

 

I would be contacting local brake retailers and see what's included in a rebuild kit.

 

That is correct Noodle. The circlip goes on the threads as shown. Make sure to rotate the circlip all the way to the bottom of the threads under the black mechanism. And the end that sticks out must go towards the end of the bolt to ensure it sits in the slots on the female end. It was a bit difficult, but I used a narrow screwdriver to continue to rotate it until it bottomed out. If you do to rotate it all the way it will not allow the piston to retract far enough into the caliper to allow the caliper to fit over the new break pads and you will need to repeat the process of removing the piston (after it has been pushed all the way to the into the caliper) and reinstall it.
After reinstalling the calipers I had an issue in which the EPB would not disengage on the tire in which I replaced the break so I had to follow the below video in which I took the EPB motor off, rotated the hex nut 2 full turns and re-installed the EPB motor.

 

I did the same thing and managed to rebuild the calliper eventually after a got hold of a new Circlip to replace the broken one. They are called a wire lock with tang not a Circlip. Have a look at this video and forward to about 2.20 mins into the video.

You Tube

 

This "wire lock with tang" circlip referred to in the posts above, is there a Mazda part number or someway/somewhere to source one?