TM 10-3930-659-34 4-6. CYLINDER HEAD ASSEMBLY REPAIR (Con’t). 3. Using  valve  spring  lifter,  compress  valve  spring (6)  and  remove  valve  spring  retaining  lock  (8) from cylinder head valve (5). CAUTION Use care not to nick or scratch surface between cylinder head  valve  face  and  stem.  A  small  nick  or  scratch  can cause cylinder head valve to break during operation. NOTE Note position of cylinder head valves in cylinder head to aid   during   installation.   Cylinder   head   valves   must   be installed in same position to prevent damage to parts. 4. Slowly   release   tension   from   valve   spring   lifter and   remove   rotator   (7),   valve   spring   (6),   and cylinder head valve (5) from cylinder head (4). 5. Repeat   steps   3   and   4   for   remaining   cylinder head valves. b. CLEANING AND INSPECTION WARNING • Carbon removing compound is a corrosive liquid. If splashed in eyes, it can cause blindness. If splashed on skin, it can cause serious burns. Always wear protective goggles or lenses, rubber apron, and rubber gloves. If accidently splashed in eyes or on skin, flush with clean, cool water. Refer to FM 21-1 1 for first aid information and seek medical attention immediately. • Compressed air used for cleaning or drying purposes, or for clearing restrictions, should never exceed 30 psi (207 kPa). Wear protective clothing (goggles/shield, gloves, etc.) and use caution to avoid injury to personnel. 1.    Soak cylinder head and cylinder head valves overnight in carbon removing compound. Using wire brush and hot water, clean all carbon deposits from cylinder head and cylinder head valves. Dry thoroughly with compressed air. 2.    Inspect cylinder head for cracks, breaks, warping, and abnormal wear. Replace cylinder head if damaged. TA708067 4-21