Abstract: A preloading pivotal pin connection arrangement for interconnecting a swivel bracket to a forked support bracket of a fluid pressure operated caliper disc brake unit. The pivotal pin includes a shoulder portion which fits snugly into a hole formed in one leg of the forked support bracket, and includes a hexagonal nut having a sleeve portion which fits snugly into a hole formed in the other leg of the forked support bracket. The intermediate portion of the pivot pin rotates freely in a bushing carried by the swivel bracket, and a locking plate prevents the backing off of the nut due to vibrations.

Abstract: A hydropneumatic brake actuator having a friction member positionable by a power piston during a brake application stroke through a lost-motion connection therewith to establish a stop to limit return movement of the power piston during a brake release and thereby provide a predetermined brake shoe clearance. The friction member comprises an elastomeric-type O-ring that can be compressed axially to varying degrees, thereby adjusting the radial force that the O-ring exerts on the piston bore.