Besides the maintenance work given in “Daily maintenance”, first order maintenance of the WD305 series diesel engine adds the following items：
(1) Check the voltage of the battery and specific gravity of the battery acid. The specific gravity of the battery acid should be within 1.28-1.29 (at ambient temperature of 15℃) and should not be lower than 1.27. Check the level of the battery acid which should be 10-15 mm above the pole plates. If insufficient, add distilled water to required level.
(2) Unscrewing oil drain plug on the the oil pan. Clean it in fuel. (If the oil is rather clean, its change period can be prolonged.)
(3) Fill all grease nipples with the proper grade of grease and fill all oil cups with lubricating oil.
(4) Diesel engine first run accumulate full 50 hours, must be replaced oil filter element; After running accumulate full 150 hours, must be replaced oil filter element to ensure that enter the high pressure oil pump of the diesel cleanness to use requirement, when change, only diesel filter together with shell from the filter holder unscrew and put on the new filter assembly to filter seat, to ensure the seal, when install the new filter, can be on the top of the seal face coated with a small amount of oil, and then screwing in filter in the seat.
(5) Move the turbocharger rotor with hand. If the rotor can not rotate freely and smoothly or stop rotating soon, this means that the bearings may be worn excessively or there occur collision or jam between rotor and its mountings or there may be severe carbon deposit on the air sealing plate of turbo back. In such a case, disassemble the turbocharger and check radial clearance and axial move of rotor to analyze probable causes and remedy them.
(6) Check the tightness of bolts of busts on connection between turbine case and middle case and tighten them if loose.
(7) Disassemble the compressor housing and clean impeller and passage of compressor housing.
(8) Clean air filter and get rid of the dirt in the collector. Take out the filter-element and clean off the dirt by vibrating or blowing with compressed air (its pressure is 98~147kPa) from the center to the outside.
Maintenance about the air filter should be done regularly as the following requirements:
① Open the back cover and clean dust gathered in dust collector for an interval of every 50-100 operation hours (determined by working condition of diesel engine).
② Take out the filter-element and clean it by vibrating or blowing with compressed air (pressure is 98~147kPa) from the center to the outside for every 100~200 operation hours.
③ Renew the filter-element for an interval of 500~1000 operation hours or the exhaust smoke is over-rich and exhaust temperature is over-high caused by filter-element choked.
④ Keep the filter-element dry and renew it while the filter-element is perforated and polluted by water or oil.
⑤ Strictly forbidden to clean the filter-element with any kind of oil and water.