Brake Caliper Rear, Checking And Cleaning
WARNING: This page is about a different car, the 2004 Volvo S40, 2003 Volvo S40, 2002 Volvo S40, 2001 Volvo S40, and 2000 Volvo S40. However, it is still accessible from the selected car via links, so may be relevant.
Clean the brake pads' contact surfaces in the brake caliper and on the caliper bracket.
Check the piston's dirt caps.
Replace the dirt cap if it is worn. If the dirt cap is defective (broken), the brake caliper has to be overhauled. See Refurbishing Rear Brake Caliper .
NOTE:
If the dirt cap is defective (broken), dirt may have entered the cylinder. Therefore, the brake caliper has to be overhauled.