24. SERVICE PROCEDURE 24.6 EVERY 500 HOURS SERVICE Maintenance for everv 50 hours and 250 hours should be carried out at the same time. 24.6.1 REPLACE FUEL FILTER CARTRIDGE l The machine is at high temperature after the engine has been operated, so never replace the filter immediately after finish- replacing the fuel filter cartridge. Prepare a filter wrench and oil container. Set the fuel container under the filter cartridge. Using the filter wrench, turn filter cartridge @ counterclockwise to remove. Clean the filter holder, fill the new filter cartridge with clean fuel, then coat the packing surface with engine oil and install it to the filter holder.
When installing, tighten until the packing surface contacts the seal surface of the filter holder, then tighten approx. a further l/2 - 314 turns. If the filter cartridge is tightened too far, the packing will be damaged and cause leakage of fuel. If it is not tightened enough, there will be a gap at the packing, and this will also cause fuel leakage, so be sure to tighten exactly to the specified tightening angle. After replacing filter cartridge 0, loosen air bleed plug 0. Loosen the knob of feed pump 0, pump it up and down, and continue until no more bubbles come out in the fuel flowing out from air bleed plug 0. Tighten air bleed plug 0, push in the knob of feed pump 0, and tighten it.
After replacing the filter cartridge, run the engine and check for any leakage from the filter seal surface. If any leakage is found, check the tightening of the filter cartridge. If there is still fuel leakage, repeat Steps 1 and 2 to remove the filter cartridge, then check the packing surface for damage or foreign material caught in the surface. If any damage or foreign material is found in the packing, replace the filter cartridge with a new one, then repeat Steps 3 to 8 to install the new filter cartridge. 3-50