a small and compact vacuum - pressure pump which serves as a portable vacuum - pressure source is disclosed . the pump includes a cylinder coupled with one handle and a piston therein coupled with another handle . a valving means with a rotatable in a cylinder allows either a vacuum or pressure to be created at a port to the valving means . the valving means which is located ahead of an inlet valve to the cylinder can adapt a preexisting vacuum pump to operate either as a vacuum pump or a pressure pump as required .