TM 10-3930-669-34 11-2. BRAKE REPAIR (CONT). NOTE There  are  four  piston  assemblies  in each intermediate cover.  They are all assembled the same way. (2) Coat  backup  ring  (24)  and  seal  (23)  with lubricating oil. (3) Install  backup  ring  (24)  and  seal  (23)  on piston (12). WARNING Use care when removing or installing snap  and  retaining  rings.    Snap  and retaining rings are under spring tension   and   can   act   as   projectiles when released and could cause severe eye injury. NOTE Ensure    cup    spring    faces    towards spacer. (4) Install   spacer   (22),   cup   spring   (21),   two spring   washers   (20),   and   retaining   ring (19) on piston (12). 11-6