The following operations if conducted within a building: lubrication of motor vehicles; brake servicing limited to servicing and replacement of brake cylinders, lines and brake shoes; wheel balancing; the testing, adjustment, and replacement or servicing of carburetors, coils, condensers, distributor caps, fan belts, filters, generators, points, rotors, spark plugs, voltage regulators, water and fuel pumps, water hoses and wiring.