Lay a tarp under the log splitter to protect the ground from spilled oil. Place a pipe wrench onto the hose coupler for the upper delivery hose of the pump. Loosen the coupling, then cap the opening to prevent leaking oil. Remove the coupling for the bottom return hose. Cap the opening.
Inspect the hoses for cracks, kinks or splitting of the exterior. Note any strange discoloration that can indicate a weakness along the material of the hose. Install new hoses and reconnect them to the pump.
Soak a rag in mineral spirits. Clean off the sap residue from the wedges and log-support beam. Apply automotive wax to all painted metal surfaces to prevent rust.
Remove the oil-filling plug. Pour hydraulic fluid into the cylinder system until reaching the three-quarter fill line. Place the screwdriver on the release screw.
Quickly turn the screw counterclockwise to retract the piston rod. This bleeds the air out of the cylinder and oil-fill system. Place the plug back onto the oil-filling opening.