Combination air cylinder and hydraulic slack adjuster

A combination air brake cylinder and hydraulic slack adjuster for a railroad car brake system including:

• a housing, an air-operated piston in said housing, an air port in said housing in communication with said air piston, a return spring in said housing for said air piston,
• a fluid outlet port in said housing, fluid piston and valve means within said housing connected to said air piston and responsive to brake application movement thereof to supply a brake shoe application fluid pressure at said outlet, said fluid piston and valve means including a first piston attached to said air piston and movable therewith, and a second piston, spaced from said first piston, and movable in response to fluid pressure forces created by movement of said first piston, a fluid reservior, check valve controlled fluid passages within a portion of said housing for connecting said reservoir with opposite sides of said second piston for adjusting slack in the brake rigging during brake application functions, said second piston having a seal portion positioned to close said check valve controlled connecting passages during brake application movement of said hydraulic slack adjuster.