Ryder Truck Rental, Inc.

An employee was prepping a piggyback air emergency spring brake chamber to later be placed on a truck in need on a service call. To cage the spring and remove hazardous energy from the internals of the part, he supplied air pressure to compress the spring and then placed the caging bolt in the hole on the end to retain the spring. When his finger was in the pinch point placing the nut on the caging bolt, the chamber lost air and actuated the spring with the bolt in it. His finger was then caught between the nut and the base of the chamber, causing skin removal and partial nail removal to his right index fingertip.