Second Brake Piston: Disassembly

WARNING: This page is about a different car, the 2008 Toyota RAV4. However, it is still accessible from the selected car via links, so may be relevant.

REMOVE 2ND BRAKE PISTON RETURN SPRING SUB-ASSEMBLY
1. Place SST on the return spring and compress.
  SST 09387-00060
2. Using a screwdriver, pry out the snap ring.
  
  Fig 1: Identifying Prying Out Snap Ring
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
3. Remove the piston return spring.
INSPECT 2ND BRAKE PISTON RETURN SPRING SUB-ASSEMBLY (See INSPECTION )
REMOVE 2ND BRAKE PISTON
1. Hold the 2nd brake piston and apply compressed air (392 kPa, 4.0 kgf/cm² , 57 psi) to the 2nd brake cylinder to remove the 2nd brake piston.
  
  Fig 3: Identifying Compressed Air To 2nd Brake Cylinder
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
REMOVE 2ND BRAKE PISTON O-RING
1. Remove the 2 O-rings from the 2nd brake piston.
  
  Fig 4: Identifying 2nd Brake Piston O-Ring
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002