Replacing Fuel Pump In 2003 Chevy Blazer: Step-By-Step Guide

Replacing the fuel pump on a 2003 Chevy Blazer can be a complex task. The fuel tank will need to be dropped, and a floor jack is recommended to slowly lower the tank down. Before beginning, ensure you have the necessary tools, including a jack and jack stands, a small flathead screwdriver, a Philips head screwdriver, and a socket wrench with an extension and socket set. It is also recommended to relieve the fuel system pressure and disconnect the negative battery cable. Once the tank is dropped, the fuel hoses and vapor hose can be disconnected from the sending unit, and the lock ring can be removed from the sending unit using a drift punch and hammer. The sending unit/pump assembly can then be removed from the tank and replaced with a new assembly. Finally, the tank can be lifted back into place, and the mounting straps, shield, and filler hose can be reinstalled.

Prepare your workspace and relieve fuel pressure

To replace the fuel pump on a 2003 Chevy Blazer, you must first prepare your workspace and relieve the fuel pressure. Here's a detailed guide on how to do it:

Park Your Vehicle in a Spacious Area:

Find a spacious area where you have ample room to work. If you have access to a lift, that would be ideal. Make sure the ground is level.

Relieve Fuel Pressure:

• Remove the fuel cap to relieve fuel pressure.
• Disconnect the negative battery terminal.
• Pre-soak any bolts or nuts with WD-40 to make the removal process easier.

Prepare the Necessary Tools and Materials:

• Rags (as the process can get messy)
• A small flathead screwdriver
• A Philips head screwdriver
• A socket wrench with an extension and socket set
• A jack and two jack stands

Disconnect the Filler Hose:

Use your Philips head screwdriver to remove the hose clamp connecting the filler hose to the gas tank.

By following these steps, you will have prepared your workspace and relieved the fuel pressure in your 2003 Chevy Blazer. Now you can proceed to the next steps of replacing the fuel pump.

Disconnect the negative battery terminal

Disconnecting the negative battery terminal is a crucial step when working on your car, especially when performing maintenance or repairs. Here are some detailed instructions on how to safely disconnect the negative battery terminal on your 2003 Chevy Blazer:

Safety First:

Before beginning, ensure your Chevy Blazer is turned off. Working on your vehicle's battery while the engine is running can cause damage to sensitive electronics. It is always recommended to take safety precautions, such as wearing gloves and safety goggles, when working on your car.

Locate the Battery:

Pop the hood of your Blazer and locate the battery. It is typically a large, block-like component located under the hood, near the engine bay's surface. In some cases, the battery may be found in the trunk, so refer to your owner's manual if you're unsure.

Identify the Negative Terminal:

Once you've located the battery, identify the negative terminal. It is usually marked with a "-" symbol and may have a black plastic cap. The positive terminal, in contrast, will be marked with a "+" symbol and typically has a red plastic cap.

Loosen the Nut on the Negative Terminal:

Using a wrench, loosen the nut on the negative terminal. Keep in mind that there is no universal size for terminal hardware, so you may need to try different socket wrench sizes to find the perfect fit. Turn the wrench counterclockwise to loosen the nut.

Remove the Negative Connector:

After loosening the nut, carefully remove the negative connector cable from the battery. Ensure that this cable is moved away from the battery and does not come into contact with it again until you are ready to reconnect.

Secure the Cable:

It is crucial to ensure that the negative cable is securely moved out of the way. You may need to use a battery cable removal tool if the cable is "seized" or attached firmly to the battery post or tray. Check with your local auto parts store or manufacturer to see if they have the necessary tool in case your battery requires it.

By following these steps, you can safely disconnect the negative battery terminal on your 2003 Chevy Blazer, making it ready for further maintenance or repairs. Remember to exercise caution and refer to your owner's manual whenever working on your vehicle.

Remove filler and vent hoses

To remove the filler and vent hoses from a 2003 Chevy Blazer, you will need to park your vehicle in a spacious area, preferably with access to a lift.

Firstly, relieve any fuel pressure by removing the fuel cap. Disconnect the negative battery terminal. Pre-soaking any required bolts/nuts with WD-40 is also recommended.

There are three lines and two electrical connectors to be removed from the fuel pump, and the filler and vent hoses that need to be removed from the back of the tank. There is also a small hose on the front part of the tank that needs to be removed.

Start by removing the skid plate. Once the skid plate is off, you will have access to the straps that hold the fuel tank in place. The forward straps will likely be rusted and not very stout, so be careful.

Once all the straps are loose, lower the tank just enough to get better access to the lines and connectors leading to the fuel pump.

Now, carefully remove the filler and vent hoses from the back of the tank. Remember where everything hooks back up. It is recommended to label the lines and take pictures with your cell phone.

Remove skid plate and tank straps

To remove the skid plate and tank straps of a 2003 Chevy Blazer, follow these steps:

Park your vehicle in a spacious area, preferably with access to a lift. If you don't have a lift, use a jack to raise the rear of the Blazer to a suitable height that allows you access to the underside of the vehicle. Place jack stands for support and safety.

Next, relieve the fuel system pressure by removing the fuel cap and disconnecting the negative battery terminal. Pre-soaking the bolts/nuts with WD-40 is recommended for easier removal.

Now, start by removing the skid plate. Once the skid plate is off, you will be able to access the straps that hold the fuel tank in place. The forward straps of the Blazer will likely be rusted and not very sturdy, so handle them carefully.

Use a floor jack with a transmission removal assembly to support the tank while removing the straps. Once all the straps are loose, carefully lower the tank just enough to gain better access to the lines and connectors leading to the fuel pump.

At this point, you can proceed to disconnect the fuel lines and electrical connectors from the fuel pump. Remember to label the lines or take reference photos with your phone to ensure proper reconnection during reassembly.

Lower the fuel tank and disconnect the fuel pump

To lower the fuel tank and disconnect the fuel pump of a 2003 Chevy Blazer, follow these steps:

First, park your vehicle in a spacious area, preferably with access to a lift. If you don't have a lift, use a jack to raise the rear of the Blazer to improve accessibility. Remember to place jack stands for safety. Next, relieve the fuel system pressure by removing the pump relay and wrapping a shop rag around the Schrader valve. Depress the stem inside the valve to release pressure.

Disconnect the negative battery cable. Then, using a Philips head screwdriver, disconnect the filler hose from the gas tank by removing its hose clamp. Remove the tank shield using a socket wrench. Now, use the jack to support the tank while you remove the straps.

Carefully lower the tank just enough to access the fuel hoses, vapor hose, and electrical connections. Press the lock tabs on the hose connectors and pull the hoses from the fittings. Now, you can unplug the electrical connections and lower the tank completely.

To disconnect the fuel pump, you will need to remove the lock ring from the sending unit using a drift punch and a hammer. Rotate the lock ring tabs counterclockwise to free the ring from the assembly. Once the lock ring is removed, the sending unit and fuel pump assembly can be taken out of the tank.

This process will give you access to the fuel pump for replacement. Remember to work cautiously and refer to a professional mechanic if you need further assistance.

Frequently asked questions