TM-9-2815-220-24 Maintenance Manual for AVDS-1790-2CA AVDS-1790-DA and AVDS-1790-2DR Engines Download
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TM 9-2815-220-24 CYLINDER ASSEMBLY REPAIR 0135 00 REPAIR (Continued) NOTE Repair valve seat inserts that did not show 360-degree contact with valve face at inspection. 7. Grind exhaust valve seat (20) using valve seat grinding kit (item 60, WP 0176) and 45-degree angle grinding stone. 8. Grind intake valve seat (21) using valve seat grinding kit (item 60, WP 0176) and 15-degree angle grinding stone. CAUTION After grinding any valve seat insert, contact area must be checked. Keep valve seat area as near as possible to center of valve face. Valves should never seat at the top or bottom of the valve face area. Premature failure will result if contact area is not correctly located. 9. Check contact area of valve seat inserts. a. Lightly blue face of two valve seats (20,21) with Prussian blue (item 25, WP 0173) and place a new or reconditioned valve (6,11) into position on valve seat. b. Rotate valves (6,11) one-half turn on insert and check for Prussian blue contact. Valve seats (20,21) must show contact all around (360 degrees), as indicated by Prussian blue transfer, to qualify as serviceable. c. When 360-degree contact is obtained, conform seat of insert to width specified (intake 0.089/0.099-inch) (exhaust 0.060/0.070-inch) by grinding inner wall and/or exposed face of insert to angles specified. 21 20 WP 0135 00-15