HYDRAULIC HAMMER

The power cell for a hammer may comprise a head, a cylinder and a piston. The head may include a main bore, a satellite bore and a lower retainer. The main bore includes an upper chamber that includes a trough, first and second furrows, and a lock wall. The trough may include a port that extends from the main bore into the satellite bore. The lock wall may extend between the furrows. The lower retainer may be disposed in the satellite bore, and may include a core member and a jut. The core member may include a bore configured to receive a fastener. The cylinder may include a body and a protrusion on the body. The cylinder may be rotatable, wherein when in a locked position the protrusion is disposed in the port, the fastener is received in the bore, and the protrusion abuts the lock wall and the jut.