Second Brake Piston: Inspection

INSPECT 2ND BRAKE PISTON RETURN SPRING SUB-ASSEMBLY
1. Using vernier calipers, measure the free length of the spring together with the spring seat.
  Standard free length: 16.61 mm (0.6539 in.)
  
  If the result is not as specified, replace the spring.
  
  Fig 1: Measuring Free Length Of 2nd Brake Piston Return Spring
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002