Loosen the nut on the bolt that fastens the wedge to the hydraulic cylinder with a wrench to remove the wedge so it can be sharpened. While the log splitter is in the horizontal position, loosen the hydraulic hose clamp to disconnect the hose from the valve. Lift the cylinder, slide the wedge forward, and lift the wedge off the log splitter. Use a bench grinder to sharpen the wedge and then reassemble the wedge, cylinder and hydraulic hose.
Remove the breather cap from the fuel tank. Flush the cap with either kerosene or warm soapy water to remove the dirt and grime buildup. Allow the breather cap to dry thoroughly before reapplying it onto the fuel tank to avoid introducing water to the fuel system.
Remove the hydraulic oil filter with an oil filter wrench. Place an oil catch pan directly underneath the oil filter to collect any wasted oil. Replace the old filter with a new filter. The oil filter should be replaced after the first 25 hours of use and every 100 hours after that. If the log splitter is used less than 100 hours in a season, the oil filter should be replaced seasonally. Check the hydraulic oil level and top it off if needed.