Hitachi DH50MB Instruction Manual - Page 18

English Wear limit No. of carbon brush 77 0.67" (17 mm) 0.26" (6.5 mm) Fig. 21 NOTE: Use HITACHI carbon brush No. indicated in Fig. 21 ⅜ Replacing carbon brushes: (For parts name, refer to Fig. 20) Loosen the tapping screws and remove the brush cap cover. Then, remove the brush caps and take out the carbon brushes. After replacement, be sure to fasten the brush caps and fix the brush cap cover firmly using the tapping screws. 6. How to replase grease This machine is full air-tight construction to protect against dust and to prevent lubricant leakage. Therefore, the machine can be used without lubrication for long periods. Replace the grease as described below. ⅜ Grease replacement period After purchase, replace grease after every 6 months of usage. Ask for grease replacement at the nearest HITACHI Authorized Service Center. Proceed for replacement of grease. ⅜ Grease replenishment CAUTION: Before replenishing the grease, turn the power off and pull out the power plug. (1) Remove the crank case cover and wipe off the grease inside. (2) Apply 0.7 oz (20 g) of HITACHI Electric Hammer Grease A (standard accessory, contained in tube) to the crank case. As the tube contains 1 oz (30 g) of grease, supply 2/3 of the contained grease. (3) After replenishing the grease, install the crank case securely. Crank Case Cover 5 Fig. 22 18