Hitachi CM4SB2 Instruction Manual - Page 15

English MAINTENANCE AND INSPECTION WARNING: Be sure to switch power OFF and disconnect the plug from the receptacle during maintenance and inspection. Using cracked, deformed or damaged wheels can lead to wheel breakage and resulting serious injury. 1. Inspecting the diamond wheel Since use of a dull diamond wheel will cause motor malfunctioning and degraded efficiently, replace with a new one without delay when abrasion is noted. 2. Inspecting the screws Regularly inspect all screws and ensure that they are fully tightened. Should any of the screws be loosened, retighten them immediately. WARNING: Using this cutter with loosened screws is extremely dangerous. 3. Maintenance of the motor The motor unit winding is the very "heart" of the power tool. Exercise due care to ensure the winding does not become damaged and/or wet with oil or water. 4. Inspecting the carbon brushes (Fig. 6) The motor employs carbon brushes which are consumable parts. Replace the carbon brush with a new one when it becomes worn to its wear limit. Always keep carbon brushes clean and ensure that they slide freely within the brush holders. Wear limit 43 (6mm) 0.24" 0.67" (17mm) No. of carbon brush Fig. 6 CAUTION: ● Using this grinder with a carbon brush which is worn in excess of the wear limit will damage the motor. NOTE: Use HITACHI carbon brush No. 43 indicated in Fig. 6. ⅜ Replacing carbon brushes: Loosen the set screw and remove the tail cover. Remove the brush caps and carbon brushes. After replacing the carbon brushes, do not forget to tighten the brush caps securely and to install the tail cover. 5. Service and repairs All quality power tools will eventually require servicing or replacement of parts because of wear from normal use. To assure that only authorized replacement parts will be used, all service and repairs must be performed by a HITACHI AUTHORIZED SERVICE CENTER, ONLY. 15