Pressure port Retaining ring Pressure cylinder (6 places) Carrier Automatic adjuster assembly (4 places) see detail A Mounting flange Reverse bleed or drain plug Bleeder valves Torque tube backing plate Pressure plate Return spring Rotor (3 places) Stator (4 places) Piston (6 places) Torque tube Rivet (typical) Adjuster ball Carrier Tube Return spring Housing Reline indicator pin Retaining pin Rivet Retainer Carrier Sleeve nut Pressure plate Keywasher Pin retainer Adjuster pin Recessed washer Lining block (14 places) surface Reline indicator pin (2 places) see detail B DETAIL A DETAIL B L Figure 13-88.  The multiple-disk brake assembly and details from a Boeing 737. They move out when brake pressure is applied, but the ball  in the tube limits the amount of the return to that equal to  the brake lining wear. Two independent wear indicators are  used on the brake illustra ted. An indicator pin attached to the  backplate protrudes  through the carrier. The amount that it  auto adjustment retraction mechanisms can be seen. Details  of the mechanisms are also shown.  Instead of using a pin grip assembly for auto adjustment,  an adjuster pin, ball, and tube operate in the same manner.  13-50