This can happen on any braking set-up, on most brakes the rubber that you see around the piston is just a dust cover, this can get compromised and cause moisture to get around the piston, this will cause corrosion on the piston. The corrosion will eat into the caliper piston and remain there to scratch away at the brake fluid bore seal, this will eventually cause the seal to become uneven and allow brake fluid to seep out of the brake caliper itself. When this happens it can leak onto your brake pads and instantly lubricate them causing the brakes to become highly dangerous, this is aside from the loss of system pressure and brake fluid from the reservoir.
If you fear your brakes are getting on a bit, a rebuild is advisable, this is a lot cheaper than replacing your brakes.
Repair, Refurb, Re-Manufacture and Coatings
We are friendly people who are incredibly passionate about our work. We love dealing with our customers, this should show on the phone. Our staff usually arrive early and stop late, because passion for what we do is a requirement to even work here.
"We just happen to refurbish brake calipers, want us to refurbish yours?"