Because of the intricacies of the job and the need to use specialized tools and equipment, that entailing reconditioning of the valves, valve seats, and valve guides known in the automobile world as valve job, should be done by a professional. A home mechanic should be capable of pulling the head, doing preliminary cleaning and wiping and then return the head to the car and deliver it to a dealer service department or an auto machine shop for the service. Performing the inspection enables identification of status of the head and valve train parts and the work as well as new parts required when dealing with an automotive machine shop. This will be done by the dealer service department or the automotive machine shop through reconditioning or replacement of the valves and valve seats, reconditioning and inspecting of the valve guides, replacing valves springs, spring retainers, rotators, and valve keepers as may be required, replacing the valve to seal with a new one and reassembly of the valved component with proper installed spring height. Also, the surface of the cylinder head gasket will be done some grinding if it has warped. Depending on professionalism of the valve job done, the head will then look as new as when it was bought. On its way back, it is necessary to clean the head once more before it is fitted onto the engine to remove any loose metal and abrasive dirt that was generated in the course of the valve grinding or in the process of surfacing the head, and to blow out all oil ways and passages with air pressure, if available, but always wearing safety goggles when using air pressure.