Because of its technicality and the type of tools and equipment used in the head, a valve job, which involves servicing of the valve seats and guides referred to as a valve job, can only be done by a professional as the valves are non-repairable. A home mechanic can be able to take off the head and undertake some rudimentary searching for dirt then take the head to an automotive machine shop where the actual head gasket services will be carried out. This inspection facilitate one in seeing the needs or work to be done on the head and valvetrain parts and new parts on engaging the machine shop. What also needs to be remembered is that there is a limit of the cylinder head-the maximum valve seat refacing dimension, which defines the amount of material that can be machined from the valve seats before it is impossible to continue the process anymore and new seats have to be installed, and this dimension mainly will be provided by the machine shop. The shop will also take out the valves and springs, refine the seats and guides, examine as well as replace the valves, valve springs, spring retainers, and keepers if necessary, replace the valve seals, set the components again, and guarantee the proper valve stem height. If the surface of cylinder head gasket is distorted it will be machined provided that the head attain the minimum specified thickness. When the valve job is done, the head will be look as new again and before placing it to the engine it must be cleaned again and all the oil galleries must free from any type of debris and abrasives which are come from the service or resurfaced time, by compressed air if it is available for blowing out of all the passages of oil holes.