A compact lubricant injector is disclosed. The injector includes an injector body having an inlet for lubricant under pressure, an outlet, and a measuring chamber for receiving lubricant from the inlet. A piston is movable in the injector body along a first axis through a stroke in the measuring chamber for the discharge of a measured volume of lubricant from the measuring chamber and thence through the outlet. A valve is movable in the injector body along a second axis different from the first axis. The valve is responsive to pressure conditions in the inlet for operation of the injector in a cycles ending in a state for venting the injector to effect recharging of the measuring chamber involving the transmission of lubricant from the inlet to the measuring chamber. A combination of at least one such lubricant injector and a manifold is also disclosed.