GMC 12550909 Valve, Exhaust

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When servicing valves, valve seats and valve guides- popularly termed as valve jobs- due to the delicate nature of the task and its specific tools and equipment, it is best when done by professional people. If doing a home mechanic work, the heads can be taken apart and reassembled, initially cleaned and inspected and then delivered to a dealer service department or an automotive machine shop for actual valve servicing. The valves and springs will be removed by either a dealer service department or an automotive machine shop who will also either recondition or replace the valves and valve seats. The valve guides will also be reconditioned; there would be checking of spring height during assembly on reassembly of the cylinder head, replacing of spring retainers or rotators replacing keepers as required, putting in new valve seals, putting together the rest of the valve parts and checking whether installed spring height is correct. In addition to that, if necking is needed on its warped surface, it may also need surfacing at this time. A professional should perform this step because in case anything goes wrong with his hands it should be his responsibility as opposed to an ameuter who will blame it on fate or bad luck. When the professional is through with doing a valve job, you'll have your head back almost new. Afterward rinse off all traces of metal particles produced from the grinding action during machining operations as well sand bar grit from contact with any grinding wheel feeds using carbide cutters which must have been used in refacing the face of combustion chambers which had gotten dirty by carbon deposits.