Replacing Stanadyne Injection Pump Fuel Shut-Off Solenoid: Step-By-Step Guide

If you need to change the Stanadyne injection pump fuel shut-off solenoid, you may be able to do so without removing the pump from the tractor. The Stanadyne DB4 injection pump is used in the John Deere 5105 tractor. To replace the fuel shut-off solenoid, you will need to remove the upper cover of the injection pump, which should have screws that allow the top to be removed without disturbing the pump. You can then access and replace the solenoid. It is important to note that you should never steam clean or pour cold water on an injection pump while it is running or warm, as this may cause seizure. Additionally, always use a backup wrench when loosening or tightening fuel lines to prevent possible internal pump damage.

Disconnecting the shut-off cable and speed control linkage

Before beginning any work on the injection pump, it is important to clean the exterior of the pump and mounting surfaces. It is crucial to never steam clean or pour cold water on the injection pump while it is running or still warm, as this can cause seizure.

Now, to disconnect the shut-off cable and speed control linkage, follow these steps:

• Locate the shut-off cable and speed control linkage: The shut-off cable and speed control linkage will be connected to the injection pump.
• Disconnect the linkage: Using the appropriate tools, carefully disconnect the shut-off cable and speed control linkage from the injection pump.
• Tag the components: Once disconnected, tag or mark the components to ensure proper reassembly.
• Set the components aside: Place the disconnected shut-off cable and speed control linkage in a safe location to avoid misplacement.

It is important to note that not all Stanadyne DB2 and DB4 injection pumps will have a shut-off cable and speed control linkage. This step should only be performed if the specific injection pump is equipped with these components.

By following these steps, you will successfully disconnect the shut-off cable and speed control linkage, allowing you to proceed with the removal and replacement of the Stanadyne DB2 or DB4 injection pump. Remember to refer to the injection pump's manual for additional instructions and safety precautions specific to your model.

Disconnecting electrical connections to the solenoid

To disconnect the electrical connections to the solenoid of a Stanadyne injection pump, you must first clean the exterior of the injection pump and mounting surfaces. It is important to never steam clean or pour cold water on an injection pump while it is running or still warm, as this may cause seizure of the pump.

Next, disconnect the shut-off cable and speed control linkage, if your model is equipped with these. Then, disconnect the electrical connection to the shut-off solenoid or throttle positioning solenoid. If your model has a cold start switch, this must also be disconnected. Tag electrical wires to ensure correct reassembly.

After this, disconnect all high-pressure injection lines. It is important to always use a backup wrench when loosening or tightening fuel lines at the injection pump to prevent possible internal pump damage.

Finally, disconnect the fuel return line and the fuel supply line.

Disconnecting high-pressure injection lines

Disconnecting the high-pressure injection lines is a crucial step when changing the fuel shut-off solenoid on a Stanadyne injection pump. Here is a detailed guide on how to safely and effectively complete this task:

Firstly, locate the injection lines. These are the lines that carry fuel from the injection pump to the engine. They are usually made of metal tubing and are connected to the injection pump by fittings or clamps. Before beginning any work, it is important to don the appropriate safety gear, including safety goggles and gloves, to protect yourself from any fuel spillage or debris.

Once you have identified the injection lines, place a drip pan or a rag beneath them to catch any fuel that may spill during the disconnection process. Fuel spillage can be dangerous and should be avoided as much as possible. Now, using the appropriate tool, loosen the fittings or clamps that secure the injection lines to the injection pump. Be cautious and gentle during this step to avoid damaging the fittings or the injection lines themselves.

After loosening the fittings, carefully pull the injection lines away from the injection pump. Again, be gentle to avoid any damage. Once the lines are disconnected, set them aside, ensuring they are secure and cannot be pulled or knocked, which could cause fuel spillage.

At this point, the injection lines are successfully disconnected from the injection pump. You can now proceed with removing and replacing the fuel shut-off solenoid. It is important to note that working on fuel injection systems can be complex and, if not done correctly, can lead to safety hazards. If you are unsure about any steps or feel uncomfortable performing this task, it is always best to consult a qualified mechanic or diesel injection specialist.

Remember to refer to the specific manual or instructions provided by the manufacturer for your particular Stanadyne injection pump model, as there may be slight variations in the process outlined above.

Removing the injection pump drive gear cover

To remove the injection pump drive gear cover, follow these steps:

Firstly, clean the exterior of the injection pump and mounting surfaces. This is an important step to ensure that no dirt or grime interferes with the removal process. Do not, under any circumstances, steam clean or pour cold water on the injection pump while it is running or still warm, as this may cause seizure.

Next, disconnect the shut-off cable and speed control linkage, if your model is equipped with these. Then, disconnect the electrical connection to the shut-off solenoid or throttle positioning solenoid, and the cold start switch, if applicable. Remember to tag the electrical wires for correct reassembly.

Now, disconnect all high-pressure injection lines. This step is important and must be done with care. Always use a backup wrench when loosening or tightening fuel lines at the injection pump to prevent altering the discharge fittings and causing potential internal pump damage.

After this, disconnect the fuel return line and the fuel supply line. You are now ready to remove the injection pump drive gear cover.

Remove the drive gear retaining nut and washer from the end of the pump shaft. Be careful not to let the washer fall inside the timing gear cover. Note that the injection pump drive gear fits snugly onto a tapered drive shaft and is indexed by a hollow pin or Woodruff key. Use a gear puller to carefully remove the drive gear from the tapered shaft, being cautious not to damage the end of the injection pump drive shaft.

With these steps completed, you will have successfully removed the injection pump drive gear cover.

Checking the injection pump mounting hole

To check the injection pump mounting hole, you must first remove the injection pump.

Step 1: Remove the Injection Pump

First, clean the exterior of the injection pump and mounting surfaces. Never steam clean or pour cold water on an injection pump while it is running or still warm, as this may cause seizure. Next, disconnect the shut-off cable and speed control linkage, if equipped. Disconnect the electrical connection to the shut-off solenoid or throttle positioning solenoid, if equipped. Disconnect the cold start switch, if equipped, and tag electrical wires for correct reassembly.

Disconnect all high-pressure injection lines, always using a backup wrench when loosening or tightening fuel lines at the injection pump to prevent possible internal pump damage. Disconnect the fuel return line and fuel supply line. Remove the injection pump drive gear cover, drive gear retaining nut, and washer from the end of the pump shaft. Be careful not to let the washer fall inside the timing gear cover.

Step 2: Check the Injection Pump Mounting Hole

Now, you can inspect the injection pump mounting hole in the cylinder block. Ensure it is clean and free of burrs.

Step 3: Inspect the Pump Mounting Surface

Also, inspect the pump mounting surface to ensure it is clean, smooth, and free of burrs.

Step 4: Inspect the Injection Pump Drive Shaft

Inspect the injection pump drive shaft for the presence of metal transfer from gear slippage. Check if the index pin in the shaft is damaged, indicating gear slippage. If the shaft shows signs of gear slippage, the injection pump is likely seized, and the cause of the seizure must be determined before reinstalling a repaired or replaced pump. The drive gear must also be changed.

Frequently asked questions