Install the piston in the brake caliper

Fig 1: Applying Thin Layer Of New Brake Fluid To Cylinders, Piston And New Sealing Ring

Courtesy of VOLVO CARS OF NORTH AMERICA.

Blow the ducts clean using compressed air.

Apply a thin layer of new brake fluid to the cylinders, the piston and the new sealing ring.

Install: 

• the piston in the caliper. Carefully press the piston to the bottom
• the dust boot in the groove on the piston. Check that everything is positioned correctly
• the rubber sleeves in the caliper for the locating pins.