TM  10-3930-638-24&P 3-5. ENGINE MAINTENANCE (cont) a. Engine Tune-up (cont). (1) Locating Top Dead Center (cont). STEP LOCATION ITEM ACTION REMARKS 2 (cont) f. Retainer, valve spring, Remove Lift  from  cylinder  head and seat for No. 1 cylinder  intake  valve NOTE Do not remove seal from valve stem. If seal is removed, valve may fall through valve guide if piston is moved too far, requiring removal  of  cylinder  head. g. Dial indicator Position On end of valve stem, with valve resting on top of No. 1 piston 3-26