Leaky brake caliper

[Scoobisteve]

Hey ya'll, still working on my brothers r1100r, and was trying to put fresh brake fluid/bleed the front brakes. The right side was leaking so I took it apart, cleaned everything up and put it back on. Went to bleed it and then the left side was leaking. I took it off thinking I would have success there as well. When I broke it apart and was wiping it clean, I noticed this crack...I also noticed that the recessed area didn't have an o-ring or anything in it? 

IMG_0871.HEIC

[Scoobisteve]

I went ahead and popped the pistons, they looked good, the inside of the cylinder looked good, I could still feel the ridge of the piston seal all the way around so I added an o-ring to the recessed area with the crack, and put it all together again...leaks just as bad as it did before...and now the right one is leaking again. Just gonna get a seal kit and see how that goes.

 

[dirtrider]

12 hours ago, Scoobisteve said:

Hey ya'll, still working on my brothers r1100r, and was trying to put fresh brake fluid/bleed the front brakes. The right side was leaking so I took it apart, cleaned everything up and put it back on. Went to bleed it and then the left side was leaking. I took it off thinking I would have success there as well. When I broke it apart and was wiping it clean, I noticed this crack...I also noticed that the recessed area didn't have an o-ring or anything in it? 

IMG_0871.HEIC 1.73 MB · 10 downloads

Morning  Scoobisteve

 

That does look like a crack, from the picture it doesn't look to have migrated into the fluid passage but I can't believe that it didn't. 

 

Even if it didn't migrate into the fluid passage it is so close that it probably will keep going until it reaches the fluid. 

 

Personally I wouldn't trust that caliper as front brakes are a fairly important safety device on a motorcycle. 

 

Those rubber (fluid passage sealing)  donuts between the caliper half's are not available from BMW but you might find an aftermarket caliper rebuild kit that has them.