Replacing The Rover 75'S Under-Bonnet Fuel Pump: Step-By-Step Guide

Changing the under-bonnet fuel pump on a Rover 75 is a job that can be done at home, but it is not a simple task. The process involves removing the battery and battery tray, as well as disconnecting various pipes and electrical connectors. It is important to note that there are two types of fuel pumps in the Rover 75: the in-tank pump and the under-bonnet pump. Both pumps typically fail in rapid succession, with the in-tank pump failing first because it feeds the under-bonnet pump, which is not strong enough to pump fuel unassisted. When replacing the under-bonnet pump, it is recommended to also replace the fuel filter, as it is located right next to the pump.

Removing the battery and tray

To remove the battery and tray of your Rover 75, you will need a 13mm ring spanner, a T40 Torx, and a flat-blade medium screwdriver.

First, remove the battery lid and securing strap with the 13mm ring spanner. Next, remove the battery terminals with the same tool. Now, lift and remove the battery from its tray. With the battery removed, you can then undo the four Torx bolts holding the tray in place using the T40 Torx. Once the bolts are removed, lift and remove the tray and its metal bottom plate.

Now, you can see and access the main plate that the battery box is fitted to. Remove any other wiring clipped to this main plate.

To reinstall the battery and tray, simply follow these steps in reverse.

Disconnecting the pipes

Locate the Fuel Pump: Open the bonnet and identify the fuel pump, which is usually located on the firewall, towards the right-hand side of the engine bay. It is a black cylindrical unit with two pipes connected to it.

Relieve Fuel Pressure: Before disconnecting any pipes, it is important to relieve the fuel system pressure. To do this, remove the fuel pump fuse from the fuse box. Then, turn the ignition on (position II) for about 5 seconds, and turn it off. Crank the engine for another 5 seconds to ensure any residual pressure is released.

Disconnect the Negative Battery Terminal: To ensure no accidental sparks, disconnect the negative battery terminal and set it aside, ensuring it does not touch any metal parts.

Release the Fuel Lines: The fuel pump is connected to two fuel lines - the feed line and the return line. Both lines need to be carefully released. Start by identifying the type of connectors used on your Rover 75. They are usually either quick-release connectors or squeeze-and-lift connectors. For quick-release connectors, press the tab and pull the line away from the connector. For squeeze-and-lift connectors, squeeze the connector with pliers and lift the line out. If your fuel lines are fitted with hose clamps, loosen them first before attempting to remove the lines.

Catch Any Spills: As you disconnect the lines, be prepared for any residual fuel to spill out. Have a clean, dry cloth ready to catch any spills and absorb any fuel that may escape. It is important to work in a well-ventilated area to prevent the buildup of fumes.

Remove the Fuel Pump: Once both fuel lines are disconnected, carefully lift out the fuel pump. It may be held in place with brackets or clips, so take note of how it is secured for easier reassembly.

Remember, always exercise caution when working with fuel systems. Ensure the area is well-ventilated, and have a fire extinguisher nearby as a safety precaution. Properly dispose of any fuel-soaked cloths, and avoid any open flames or sparks during the process.

Removing the main plate

With the battery removed from its tray, you can see and undo the four Torx bolts holding the tray in place. Use a T40 Torx socket bit or tool to do this. Remove the tray and its metal bottom plate and set it down with the battery close by on the floor.

You can now see the main plate the battery box is fitted to. Remove any other wiring clipped to the main plate around its sides. Attached to this is the UBFP. The pump is secured to the main plate by a bracket, which is held by a single 8mm bolt. This bolt can now be removed using an 8mm socket so the bracket can be released. The bracket has a T-fixing joint that slots into the main plate opposite the bolt, and can be released from the plate.

Now unplug the wiring from the top of the UBFP by pressing the tab on the wiring plug. With the wiring plug to the pump out of the way, release the servo pipe/tube from its brackets. This gives you that extra bit of room when removing the UBFP. Follow the pipe further back toward the servo and unclick at least three joints.

Now the wiring and the servo pipe have been removed and are out of the way, the main plate will pull toward you. Again, make sure no other wires are clipped to the plate. With the main plate pulled towards you a little, you gain more access so you can remove the UBFP bracket from the plate. Put the bracket to one side, on the engine cover or with the battery and its tray.

Disconnecting the wiring

First, locate the battery and its lid. Using a 13mm ring spanner, remove the securing strap and then remove the battery terminals. You may need a 10mm socket if your model has a lower bolt. Lift the battery out of its tray. With the battery removed, you will be able to access and undo the four Torx bolts holding the tray in place using a T40 Torx socket.

Once the tray and its metal bottom plate are removed, you will see the main plate that the battery box is fitted to. Remove any wiring clipped to this main plate. The under-bonnet fuel pump (UBFP) is attached to this plate. To disconnect the wiring from the UBFP, locate the wiring plug at the top of the UBFP and press the tab to unplug it.

Now that the wiring has been disconnected from the UBFP, you will need to release the servo pipe/tube from its brackets. Follow the pipe towards the servo and unclick at least three joints. Ensure that no other wires are clipped to the main plate, as you will now pull the main plate towards you to gain more access.

At this point, you will be able to remove the UBFP bracket from the plate. Place the bracket safely on the engine cover or with the battery and tray. The UBFP is now free but take care not to twist it too much as you may damage the T-joint below. Place some old rags under this joint and over the ABS module to avoid any spills.

The next step is to release the fuel pipe going into the low-pressure pump on top of the fuel filter. Before releasing it, place a rag under the joint and then press the two clips to remove it. With the fuel pipe removed, you will have better access to the bottom jubilee clip holding the UBFP to the fuel line at the T-junction.

Use a small screwdriver to slot into the square hole on the clip and twist to undo it. Now, slowly and carefully, twist the UBFP out of the pipe. If it is stiff, use the end of the small screwdriver to gently prise the rubber pipe down to help release it.

The UBFP can now be removed, taking care not to spill any diesel fuel. Be sure to clean up any spills immediately.

Replacing the pump

The under-bonnet fuel pump is not too difficult to replace, but it will take some time and effort. Here is a step-by-step guide on how to do it:

• Remove the battery lid and securing strap using a 13mm ring spanner or a 10mm socket, depending on your model.
• Remove the battery terminals with a 13mm spanner.
• Lift and remove the battery from its tray.
• Undo the four Torx bolts holding the tray in place using a T40 Torx socket or tool.
• Remove the tray and its metal bottom plate.
• Locate the main plate that the battery box is fitted to. Remove any wiring clipped to the sides of this main plate.
• The under-bonnet fuel pump (UBFP) is attached to this main plate by a bracket and a single 8mm bolt. Remove the bolt using an 8mm socket to release the bracket.
• Unplug the wiring from the top of the UBFP by pressing the tab on the wiring plug.
• Release the servo pipe/tube from its brackets to gain extra room when removing the UBFP. Follow the pipe further back toward the servo and unclick at least three joints.
• With the wiring and servo pipe removed, carefully pull the main plate towards you, ensuring no other wires are clipped to it.
• With the main plate pulled forward, you will have more access to remove the UBFP bracket from the plate. Place the bracket safely on the engine cover or with the battery.
• The UBFP is now free but try not to twist it too much as you may damage the T-joint below it. Place rags under this joint and over the ABS module to avoid any spills.
• Release the fuel pipe going into the low-pressure pump on top of the fuel filter. Before releasing, put a rag under the joint and press the two clips to remove it.
• With the fuel pipe removed, you can now access the bottom jubilee clip holding the UBFP to the fuel line at the T-junction. Use a small screwdriver to twist and undo the clip.
• Carefully twist the UBFP out of the pipe. If it is stiff, use the end of the small screwdriver to gently prise the rubber pipe down to help release it.
• Remove the UBFP, being careful not to spill any diesel fuel. If there are any spills, clean them up immediately.
• For refitting, have a couple of jubilee clips ready. Push the new UBFP into the fuel pipe T-junction and fit and tighten the jubilee clip at the bottom using a medium screwdriver.
• Fit the bracket around the new UBFP.
• Push the top UBFP hose into the low-pressure pump.
• Fix the bracket to the main plate using the 8mm bolts removed earlier.
• Refit any other wiring that was removed from the main plate.
• Line up the main plate and battery box with the securing holes, then fit the battery box and inner plate using the four T40 Torx bolts.
• Replace the battery and its securing strap.
• Refit the positive and negative terminals to the battery, remembering to open the ends with a medium screwdriver for a nice tight fit. Do not over-tighten the nuts on the terminals as they will work loose due to the taper on the battery poles.

And that's it! You have now successfully replaced your under-bonnet fuel pump.

Frequently asked questions