Much work is involved in the overhaul of the valves, valve seats and the valve guides usually referred to as the job or v- job and should, therefore, be done professionally. Home mechanic can unbolt the heads, do preliminary washing and examination, and then reinstall them and take the heads for other service to a dealer service department or an automotive machine shop. This way the head and the valve train components condition can be estimated and the work needed and the new parts required when dealing with an automotive machine shop can be known. The dealer service department or automotive machine shop will change the valves and springs off; recondition or replace the valves and valve seats; recondition the guides; check or replace the valve springs, spring retainers and keepers as necessary; replace the valve seals with new ones ; assemble the valve components; and check that the installed spring height is correct. Also, the cylinder head gasket surface will be resurfaced if it is warped or otherwise deformed in some way. This operation when done proficiently restores the head to its factory fresh state and this is achieved through the valve job. When it comes back it must again be cleaned prior to re assembly on the engine especially after valve service or head machining because there may be metal particles and some abrasive grit which must be cleaned out using compressed air if available blow all oil holes and passages.
