Drum brake wheel cylinder with internal automatic adjustment

A wheel cylinder in a drum brake, comprising a wheel cylinder having a longitudinal through bore receiving slidably therein a pair of opposed pistons, each piston engaging a web of an adjacent drum brake shoe, a first of said pistons having therein a longitudinal opening receiving a friction rod and a through opening receiving slidably therein an adjuster release mechanism, the second of said pistons having a recess opening receiving therein a second end of said friction rod, a friction latch adjusting lever located about said friction rod to engage the first piston and located adjacent said adjuster release mechanism, the friction latch adjusting lever comprising a generally rectangular member having a central opening receiving therethrough the friction rod, a pair of downwardly extending tangs defining a slotted opening receiving therein the adjuster release mechanism, and an upper laterally extending tang which engages a side wall of said first piston, spring means disposed about said friction rod to abut at one end said second piston and abut at the other end the adjusting lever, means for effecting a running clearance and disposed within the recess of the second piston so as to define a running clearance with the second end of said friction rod, so that hydraulic pressure received within said longitudinal through bore displaces said pistons away from one another whereby displacement of the second piston beyond said running clearance causes the second piston to displace the friction rod relative to the friction latch adjusting lever which advances along the friction rod to an adjusted position so that an at-rest position of the pistons relative to one another is adjusted in accordance with wear of linings on the brake shoes.