Replacing Fuel Pump In '99 Blazer: Step-By-Step Guide

If you own a 1999 Chevrolet Blazer, you may need to replace the fuel pump due to a variety of issues, such as poor acceleration, low mileage, or a stalled engine. Before attempting any repairs, it is important to disconnect the negative battery cable and bleed the pressure off the system. The fuel pump is located inside the fuel tank, which can be accessed by raising the vehicle, removing the fuel filler and vent hoses, and lowering the tank. Once the tank is lowered, you will be able to access the fuel line fittings and electrical connections. It is crucial to capture any fuel that is bled off into a safe container to avoid accidents.

Disconnect the negative battery cable and bleed the pressure off the system

Disconnecting the negative battery cable and bleeding the pressure off the system is an important step when changing the fuel pump in a 1999 Blazer. This is a safety measure to prevent any accidental ignition of fuel vapours during the repair process. Here is a detailed guide on how to do this:

Firstly, locate the negative battery cable. This will be attached to the negative terminal of the battery, which is usually marked with a '-' symbol or a black cover. Once located, proceed to carefully disconnect the cable. It is important to only disconnect the negative cable and not the positive one, as this could result in an accidental short circuit. Ensure that you do not let the cable touch any metal parts of the car during or after removal, as this could cause a short circuit.

Next, you will need to bleed the pressure off the system. This is done to release any built-up pressure in the fuel lines and tank. Locate the fuel lines coming out of the fuel tank and trace them to the fuel filter, which should be along the frame rail by the driver-side door. You can then pull the quick-disconnect fitting off the outlet side. The quick-disconnect is equipped with a locking tab that can be easily pulled up, allowing the fitting to slide off. Be cautious, as fuel may spill during this step. It is important to always capture any fuel that you bleed off into a safe container to prevent spills and reduce the risk of fire.

After disconnecting the cable and bleeding the pressure, you can proceed with the next steps of lowering the fuel tank and replacing the fuel pump, as outlined in other guides. Remember to always exercise caution when working with fuel systems to ensure your safety and the protection of your vehicle.

Remove the fuel filler and vent hoses

To remove the fuel filler and vent hoses from your 1999 Chevrolet Blazer, you will first need to disconnect the negative battery cable and bleed the pressure off the system. Remember to capture any fuel that you bleed off into a safe container. Next, raise the vehicle to gain access to the fuel tank.

Now, you can remove the fuel filler hose and then the fuel vent hose. Once these are removed, you will need to remove the straps and start lowering the tank. When the tank is lowered, you will have access to the fuel line fittings and electrical connections. It is important to note that there may still be some residual pressure at this point, so be cautious and continue to capture any fuel in a safe container.

Before reinstalling the new fuel pump, you will need to follow additional steps outlined in the fuel pump replacement guide. These steps include disconnecting the electrical connection, fuel line fittings, and emissions tube, as well as cleaning the outside and inside of the tank to prevent debris from entering.

Disconnect electrical connections and fuel line fittings

To disconnect the electrical connections and fuel line fittings of your 1999 Blazer, follow these steps:

Begin by raising the vehicle to gain access to the fuel tank. First, remove the fuel filler hose, then the fuel vent hose. Next, remove the straps and start to lower the tank. Once the tank is lowered, you will have access to the fuel line fittings and electrical connections.

Now, disconnect the electrical connection by first removing the safety retainer. Then, disconnect the fuel line fittings. There may be residual pressure at this point, so be cautious and have a safe container ready to capture any fuel.

Before removing the fuel pump module, clean the outside of the tank to prevent any unwanted debris from entering. Now, you can remove the locker ring, but note that you will need to depress the safety retainer on the lock ring. Turn the locker ring counterclockwise with a brass nonferrous punch. Inspect the locker ring to ensure it is not damaged in any way that would hinder reinstallation.

Now that you have disconnected the electrical connections and fuel line fittings, you can proceed to remove the fuel pump module and continue with the rest of the fuel pump replacement process. Remember to always exercise caution when working with fuel systems.

Remove the fuel pump module and clean the tank

To remove the fuel pump module and clean the tank of your 1999 Chevy Blazer, follow these steps:

First, you will need to disconnect the negative battery cable to bleed the pressure off the system. Ensure that you capture any fuel that is bled off into a safe container. Next, raise the vehicle to access the fuel tank. Remove the fuel filler hose and the fuel vent hose. Now, remove the straps and start to carefully lower the tank. Once the tank is lowered, you will have access to the fuel line fittings and electrical connections.

Disconnect the electrical connection by removing the safety retainer. Then, disconnect the fuel line fittings, being cautious of any residual pressure, and capture any fuel in a safe container. Disconnect the emissions tube at the front of the tank, and remove the fuel line retainers to reuse them on the new pump module.

Before removing the fuel pump module, clean the outside of the tank to prevent any debris from falling into it. Now, you can remove the locker ring by depressing the safety retainer and turning it counterclockwise with a brass nonferrous punch. Inspect the locker room for any damage that could hinder reinstallation.

With the locker ring removed, take out the fuel pump module from the tank. At the bottom of the assembly, there is a reservoir, so be sure to capture any fuel in a safe container. Now, drain the remaining fuel from the tank into a safe container, and proceed to clean the inside of the tank thoroughly. It is important to ensure that the tank is as clean as possible to provide a clean environment for the new fuel pump.

Once the tank is clean, you can install the new fuel pump module.

Reinstall the new fuel pump module and reconnect the electrical connections

Now that we've cleaned the inside of the tank, we can install the new fuel pump module. Within the installation kit, there is a tank seal, a GM wiring connector that may be used on some applications, and assorted instructions. The sender arm is attached to the fuel pump reservoir. Remove the red protecting cap on the end of the sender arm. Now, install the float arm into the sender assembly, making sure that it fully snaps into place before installing the pump module into the tank.

Install the tank seal about halfway up on the module, using a light lubricant around the bottom edge of the plans to help with installing it into the seals on the top of the fuel pump flange. There is a locating tab on the bottom edge of the plans. Also, in the top of the tank is the location where this tab will set. Position the sealing ring into place, making sure it is fully seated into position, and install the lock ring. Now, take the nonferrous brass punch and complete the installation of the tank ring. Always note that the safety retainer is fully seated into the locker room.

Before reinstalling the tank into the vehicle, insert the fuel line retainer clips into the end of the fuel lines. Be sure to inspect the end of the fuel line fitting to make sure that it is not damaged. Now, we're ready to reinstall the tank into the vehicle. We will need to reposition the fuel filler hose and vent hose onto their fittings, reconnect the emissions line on the front of the tank, and reattach the fuel line connections and our electrical connection. Always be sure to reinstall the safety retainer on your electrical connection. We can now reinstall the tank straps, reconnect the negative battery cable, and cycle the key 2-3 times to recharge the system.

Once the system is recharged, start the vehicle and monitor the fuel pressure to make sure that it is within vehicle specifications. Remove the gauge, shut the engine off, and bleed the pressure from the system using the pressure relief on the gate, making sure to capture any fuel in a safe container.

Frequently asked questions