NMWR-9-2815-220 Overhaul Manual for M60 M88 Engine AVDS-1790-2CA, AVDS-1790-2DA, AVDS-1790-2DR Download
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NMWR 9-2815-220 CYLINDER ASSEMBLY OVERHAUL—Continued 0012 00 REPAIR – Continued (b) Valve rocker arms. (1) Bearing sleeves. If bushing is worn or damaged, rocker arm must be replaced. Refer to OIP (Table 7 and 11). (2) Adjusting screw. Replace the adjusting screw when threads are stripped, damaged, or when screw binds in the rocker arm. Also replace adjusting screw when swivel pad does not rotate freely on the screw. ASSEMBLY 1. Refer to WP 0005 00 for general assembly procedures. 2. Assemble cylinder assembly in accordance with TM 9-2815-220-34. 3. Valve leakage test. After assembly, test valves for leakage by filling the intake and exhaust ports with fluid and checking for leakage inside the cylinder bore. No leakage is allowed. Optional: after assembly, test valves for leakage by sealing skirt end of cylinder and nozzle opening, and applying 60 + 5 psi (414 + 34 kPa) air pressure to cylinder combustion chamber. With air source shut off, leakage rate from original pressure shall not exceed 14 psi (97 kPa) in 15 seconds. If the leakage exceeds 14 psi (97 kPa), observe intake and exhaust ports to determine if leakage is from valve or hardseat. If leakage is from valve, reject, if leakage is from hardseat, accept up to 24 psi (165 kPa) leakage in 15 seconds. If both valve and hardseat leak, retest with rubber coated valves. If leakage rate is above 10 psi (69 kPa) in 15 seconds, accept. 0012 00-16 Change 1