Hitachi DH40MRY Instruction Manual - Page 12

English MAINTENANCE AND INSPECTION WARNING: Be sure to switch power OFF and disconnect the plug from the receptacle during maintenance and inspection. 1. Inspecting the drill bits NOTE: Since use of a dull tool will cause motor Use HITACHI carbon brush No.73 indicated in Fig. malfunctioning and degraded efficiency, replace 20 the drill bit with a new one or resharpening without ⅜ Replacing carbon brushes: delay when abrasion is noted. (For parts name, refer to Fig. 1) 2. Inspecting the screws Loosen the two set screws and remove the tail Regularly inspect all screws and ensure that they cover. Remove the brush caps and carbon brushes. are properly tightened. Should any of the screws After replacing the carbon brushes, tighten the be loose, retighten them immediately. brush caps securely and to install the tail cover with securely tightening two set screws. WARNING: 5. How to replase grease Using this Rotary Hammer with loosen screws is This machine is full air-tight construction to protect extremely dangerous. against dust and to prevent lubricant leakage. Therefore, the machine can be used without 3. Maintenance of the motor lubrication for long periods. Replace the grease as The motor unit winding is the very "heart" of the described below. power tool. Exercise due care to ensure the ⅜ Grease replacement period winding does not become damaged and/or wet After purchase, replace grease after every 6 with oil or water. months of usage. Ask for grease replacement at 4. Inspecting the carbon brushes: (Fig. 20) the nearest HITACHI Authorized Service Center. The motor employs carbon brushes which are Proceed for replacement of grease. consumable parts. When they become worn to or ⅜ Grease replenishment near "wear limit", it could result in motor trouble. When an auto-stop carbon brush is equipped, the CAUTION: motor will stop automatically. At that time, replace Before replenishing the grease, turn the power off both carbon brushes with new ones which have and pull out the power plug. the same carbon brush Nos. shown in the figure. In addition, always keep carbon brushes clean and (1) Remove the crank cover and wipe off the grease ensure that they slide freely within the brush inside. holders. (2) Apply 1.0 oz (30 g) of HITACHI Electric Hammer Grease A (standard accessory, contained in tube) CAUTION: Using this Rotary Hammer with a carbon brush which is worn in excess of the wear limit will damage the motor. to the crank case. (3) After replenishing the grease, install the crank cover securely. Crank cover Wear limit No. of carbon brush 73 0.67" (17 mm) 0.28" (7 mm) Fig. 20 12 Fig. 21 NOTE: The HITACHI Electric Hammer Grease A is of the lower viscosity type. When the supplied grease tube is consumed, purchase from a HITACHI Autorized Service Center.