TM-9-2815-200-35 Maintenance Manual for AVDS-1790-2M AVDS-1790-2A and AVDS-1790-2AM Engines Download
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Figure 6-57. Ultrasonic search fixture installed in cylinder barrel mounting flange. (d) With the search fixture UPPER- LOWER switch in the “UPPER” position, move the search fixture probe through the full upward and downward travel. Note. When a heavy pulse echo enters the right hand edge of the gate (view F, fig. 6-53), the detector has reached the maximum down- ward travel. Any alarm indicates a crack or defect in the cylinder. Re-inspect the defect suspect area. If the alarm sounds again, the cylinder must be scrapped. Note. Should the inspection reveal an abnormally high cylinder reject rate, the tester adjustments should be checked to be certain the readings are correct. (e) A signal appearing immediately to the left of the gate indicates cylinder bore roughness. The gate start may require minute adjustment to the right to exclude this extraneous signal. (f) Remove the search fixture from the cylinder, empty the water, and remove the plug from the bottom of the cylinder bore. If the cylinder has no defects, treat it to prevent rust. 6-33. Repair a. Cylinder Interior. (1) Valve guide replacement. (a) Replace any cracked, galled, eroded, or scuffed intake and exhaust valve guides (14 and 37, fig. B-4) or guides which do not conform to limits specified in overhaul standards (table 6- 15). Replace and ream valve guides following instructions which accompany figures 6-58 through 6-62. Note. The intake and exhaust valve guides are removed from the cylinder in the same manner. Mechanical puller - 5120-448-0400 is used for intake valve guide removal and mechanical puller - 5120-448-0401 is used for exhaust valve guide reinoval. 1. Insert screw of mechanical puller - 5120-448-0400 through the valve guide and puller (A). 2. Install nut (B) on end of puller screw and tighten to remove valve guide from cylinder. Figure 6-58. Removing intake valve guide using mechanical puller - 5120-448-0400. 6-66