Yanmarshi Diesel Engine Oil Pump Maintenance Procedures
The maintenance steps for the Yanmar diesel engine oil pump are as follows:
Preparatory work
Prepare the necessary tools, such as wrenches, screwdrivers, hex wrenches, etc., as well as diesel for cleaning and clean cloths.
Make sure the engine has been shut down and cooled down, and cut off the power supply to prevent accidental start-up during the maintenance process.
Remove the external connection pipes
Remove 4 high-pressure oil pipes, the intake oil hose, and the return oil hose. Mark the positions of the pipes carefully for subsequent installation.
Remove the intake water hose and the return water hose (some models may have a cooling water connection).
Disassemble the ignition electromagnetic valve.
Carefully remove the ignition electromagnetic valve. Pay attention to preserving the screws, gaskets and other small parts that are removed, to avoid losing them.
Remove the oil valve
Remove the four oil outlet valves, take out the oil outlet valve spring, valve core, steel balls and other components. Clean them thoroughly with diesel and place them in the correct order to avoid confusion or loss.
Remove the fixing screws of the pump head
Remove the right screw 2 on the pump head. Pay attention to keeping the screw, copper gasket and filter screen.
Remove the left screw 1 on the pump head and take out the plunger valve core. Pay attention to the direction of the notch on the plunger valve core and make a mark. When reinstalling, keep it in the original position.
Disassemble the pump head
Remove 4 hex socket screws, loosen the side screws, rotate the limit block 90° to the left, and then remove the pump head.
Inspect and replace the components
Check the wear conditions of components such as the plunger, oil outlet valve, and pump body. If there is severe wear, scratches, or damage, new components need to be replaced.
If replacing the pump head, ensure that the new pump head is compatible with the original pump body. Before installation, remove the rubber cover of the new pump head.
Install the pump head
Place the new pump head vertically on the pump body. Use your right hand to gently press the pump head into place. At the same time, insert your middle finger of your left hand into the installation hole of the stop electromagnetic valve and push the rocker lever to align the pawl wheel with the bottom wheel groove. Ensure that the pump head is installed properly before tightening the 4 internal hexagon screws.
Install the plunger valve core
Install the new plunger valve core in the direction indicated by the mark, and press it down gently to the proper position.
Install the oil outlet valve and other components.
Install four oil outlets, ensuring that the oil outlets are securely installed and have good sealing.
Install the flameout electromagnetic valve, high-pressure oil pipe, intake rubber hose, return oil rubber hose, water inlet pipe, and water outlet pipe, and check whether all connections are tight and there is no leakage.
Remove air from the oil circuit
Turn the key of the ignition switch clockwise to the first position (to turn on the power), but do not start the engine. Loosen the fuel inlet pipe connected to the fuel injection pump until diesel flows continuously and without bubbles. Then tighten the fuel inlet pipe.
Loosen the high-pressure fuel pipe and observe if there is a regular fuel injection. If the fuel injection is normal, it indicates that the air in the fuel line has been expelled.
Inspection and Testing
Completely check whether all components are installed correctly, and whether there are any missing or loose parts.
Start the engine and check if the oil pump is working properly, for any abnormal noises, leaks or other issues. Observe if the engine is running smoothly. Notes:
During the maintenance process, the components need to be kept clean to prevent impurities from entering the oil pump.
If you are not familiar with the maintenance operation, it is recommended to have it done by professional maintenance personnel to avoid damage.
When replacing components, it is advisable to use original factory parts to ensure compatibility and performance.
