4. Install the piston seal back up ring (7), piston seals (6) and piston (5).
a. Install the piston seal back up ring in the brake housing.
b. Lubricate the outside diameter of the piston, housing bore and piston seals with the same fluid used in the brake actuation system.
c. Install the first piston seal with the hard plastic heel on the seal back up ring. The rubber part must be toward you. Figure 78.