Replace Fuel Pumps

Replacing a fuel pump is not the same for every engine, but these basic steps are a good place to start.

Preparation

Before you begin work on the diesel fuel pump, you need to prepare the engine. Refer to your Operation and Maintenance Manual (OMM) for detailed instructions.

• Ensure the pressure is relieved in the fuel system by leaving the engine switched off for a period.
• Disconnect the electrical system, removing the earth (negative) and then the positive from the battery terminals, before starting any work on the engine.

Removing the old pump

The typical process to remove the fuel injection pump is:

1. Remove the fuel injection lines.
2. Remove the crankshaft pully.
3. On mechanical fuel systems, remove the front cover, along with the coolant pump.
4. Ensure that number one cylinder is at top dead centre.
5. Disconnect the fuel feed and return lines.
6. Disconnect the wiring assemblies, such as cold start and auto shut-off.
7. Loosen the locking screw on the fuel pump and rotate the spacer to allow the locking screw to tighten against the shaft of the fuel injection pump. Rotate the fuel pump gear counter clockwise, remove the backlash and tighten the locking screw.
8. Remove the nut and the washer from the shaft of the fuel injection pump. And use a suitable puller to remove the fuel injection pump gear. Do not pry the fuel injection pump gear from the shaft of the fuel injection pump.
9. Remove the setscrews and brackets to remove the fuel injection pump from the cylinder block.

Put identification marks on all fuel hose and tube assemblies to enable correct re-installation. Remember to plug all fuel hose and tube assemblies with suitable plastic plugs to prevent fluid loss, and prevent contaminants entering the system.

Install the new pump

The shaft of the fuel injection pump must remain locked until the timing gear has been installed and tightened onto the shaft of the fuel injection pump. Should the shaft of the fuel pump be rotated accidentally, the fuel injection pump must be returned to your Perkins distributor.

1. Ensure that the number one cylinder is at top dead centre on the compression stroke.
2. Install the new O-ring on the pump and mount the pump on the engine with the setscrews.
3. Position the fuel injection pump gear on the end of the fuel pump shaft and rotate the gear counter-clockwise to remove backlash, and tighten the locknut.
4. Connect the electrical harnesses and fuel feed and return lines.
5. Loosen the locking screw and move the space to prevent the locking screw from tightening against the shaft of the fuel injection pump.
6. Tighten the nut on the crankshaft timing gear.
7. Complete the process by installing the crankshaft cover, pulley and installing the fuel injection lines.

Purge and get ready

When a fuel pump is removed, or fuel lines disconnected, the fuel system will need to be purged of any air. The process is simple and can be found in the OMM. Don’t forget to replace the fuel filter as well so that your new pump runs smoothly.

For more information, contact your local Perkins distributor.