Hitachi NT65MA3 Instruction Manual - Page 20

9-3. Possible Causes and Correction of Air Leakage Air leakage repair location Repair procedure (1) Check the points of the following parts marked by an asterisk for abnormal condition. (2) Next, check the seal parts (marked with a double circle) for wear, flaws and damage. (3) And then, check other places. Air leakage point (A) Exhaust port (B) Exhaust cover Possible cause With control valve OFF With control valve ON Head Valve (A) [10] and the Cylinder [11] are abnormal (seal surface of the b portion is worn or deformed). The O-ring (I.D 20.8) [9] is abnormal (worn, deformed or damaged). Head Valve (A) [10] is abnormal (worn, deformed or damaged). Head Valve (A) [10] is abnormal ( a portion is worn, deformed or broken). The Exhaust Cover [5] is abnormal ( a portion is deformed or clogged with dust). The Hex. Socket Hd. Bolt (W/Sp. Washer) M5 x 25 [4] is loose. The Gasket [6] is damaged. The seal surface of the Body Ass'y [30] or the Exhaust Cover [5] is abnormal. --- 17 ---