TM 10-3930-669-34 VISUAL INSPECTION (1) Remove   valves   from   suspect   cylinder   head(s) (Para 3-6). (2) Inspect valves and springs for damage. (a) If valve(s) and/or spring(s) is damaged,   replace   valve(s)   and/or spring(s)  or  cylinder  head(s)  (Para 3-6 or 3-5). (b) If     valves     and     springs     are     not damaged,  valves  and  springs  are OK. VISUAL INSPECTION (1) Inspect  inside  of  suspect  cylinder(s)  and  engine block for scoring. (a) If  there  is  scoring,  piston  rings  faulty. Replace  piston  rings  (Para  3-13)  and cylinder(s)    (Para    3-17)    or    replace engine (Para 3-3). (b) If  there  is  no  scoring,  go  to  Step  (2) below. (2) Measure trapezoidal, taper-faced, and oil control rings (Table 3-1). (a) If  piston  ring(s)  is  not  within  limits, replace piston ring(s). (b) If    piston    rings    are    within    limits, piston rings are OK. (3) Install cylinder(s) (Para 3-7). (4) Install valves and springs (Para 3-6). (5) Install cylinder head(s) (Para 3-5). (6) Install engine blower ducting (Para 6-2). (7) Install cab (TM 10-3930-669-20). 2-45