Broken caliper piston

[S J SAVAGE]

Hi littleredrooster

By the sounds of it I think you are due a good shudder !!!

Cheers

 

[Straypuss]

Littleredknobhead

Says it all really

 

[littleredrooster]

Thanks for that, straypuss.

 

[zerocool]

Took my caliper off to replace my brake pads to find presumably the same issue as with this.

Somebody has obviously tried pushing back a stiff piston on the left caliper and put a nice hole in the spacer which I propably didnt make any better as I had to force the piston back too as it was bloody stiff. However I did the use the old pad to move it back but sure that wont help as it was REALLY STIFF!!!

Im guessing as with previous comments that its not unsafe as the hole is no deeper in the spacer than the manufacturers hole which already exists.

Im going to enquire with the dealers as to if they will sort it under warranty but I imagine they will blame me.

While I agree with the safety first comments, if its just a plastic spacer then surely it will not effect braking performance and if there is just a chip in the center of the contact point it shouldnt effect pad spacing either???

 

[zerocool]

Found this pic, dunno if it proves that the insert shouldnt affect brake fluid pressure or not...

 

[zerocool]

My dealer had a look at the top of the piston and said it was fine as its just the top and not the actual piston itself. He was worried about the piston sticking but I think I sorted that myself.

the ZC

 

[pomm001]

Having said all that, if it was me I'd take the opportunity to completely strip and clean the caliper.

You usually don't need to replace the seals unless they are damaged, but cleaning the grooves in which they sit is important to do every year or so. The dirt building up behind the seal eventually clamps the piston tight and your brakes stop working

Disclaimer - never owned or serviced a BMW, just speaking from general experience with various bikes over the years.

Agree with Mouse regarding the seals
you will need about three pairs of hands if you are going to try this without taking the caliper off, dont even consider it , it will end in tears
it can be bl**dy tricky trying to get the pistons out even on the bench .
dont force them out, air pressure would be best, but again if you have any doubts and want to play the piano ( loss of fingers ) pay someone to do it for you !
When all cleaned out, (and its important to remove the seals and clean out the corrosion behind them) the pistons should push in with freely by hand.
best of luck

 

[Keith Chapman]

Mechanical ineptitude?
I stripped my first vespa engine when I was 11!!!

And it is still in a box waiting a rebuild