Replacing Fuel Pump In '99 Chevy 1500: Step-By-Step Guide

If you're looking to replace the fuel pump on your 1999 Chevy 1500, you're not alone—it's a common problem. The good news is that it's a task you can tackle yourself, and it will save you a lot of money compared to taking it to a professional. There are two methods for replacing the fuel pump: removing the bed or dropping the fuel tank. Here's a step-by-step guide to help you get the job done right.

How to Change Fuel Pump on 1999 Chevy 1500

Remove the bed vs. drop the fuel tank

There are three ways to access the fuel pump on a 1999 Chevy 1500: dropping the fuel tank, lifting the bed up, or cutting a hole in the bed. Dropping the fuel tank is considered the easiest method. However, it requires draining the fuel tank and typically involves three people and a lift.

An alternative method is to lift the bed of the truck. This can be done by loosening the rear two bed-to-frame bolts and removing the other six. This provides clear access to the fuel tank without fully removing the bed. This method may be preferred if you are working alone and do not have access to a lift.

Another option is to cut a hole in the bed of the truck. This method is more invasive and requires careful measuring and cutting with a die grinder. While this method provides access to the fuel pump, it may not be suitable for those who want to avoid making permanent modifications to their vehicle.

When deciding between removing the bed and dropping the fuel tank to change the fuel pump on a 1999 Chevy 1500, consider your resources, the time you want to spend, and how comfortable you are with making modifications to your vehicle.

Disconnect the fuel tank filler hose

Disconnecting the fuel tank filler hose is a crucial step in changing the fuel pump on a 1999 Chevy 1500. Here is a detailed guide on how to do this:

First, locate the fuel filler neck. This is a large-diameter hose that is connected to the fuel tank with a hose clamp. It can be found on the driver's side of the tank, above the frame. To disconnect the hose, you will need to loosen the hose clamp. Using a stubby flat-head screwdriver, turn the hose clamp counter-clockwise to loosen it. Be careful not to strip the metal on the hose clamp, as this can make it difficult to tighten again. Once the hose clamp is loose, you should be able to pull the fuel filler neck off fairly easily.

Before disconnecting the hose, it is important to relieve the fuel line pressure. This can be done by pulling the fuel pump relay from the fuse box and starting the vehicle, letting it run until it shuts down. Working in a well-ventilated area, free of any heat sources, sparks, and open flames, is crucial when working with fuel lines. Do not smoke while performing this task.

Once the fuel filler neck is disconnected, move on to the next step of disconnecting the fuel tank lines. This will involve disconnecting multiple lines on the passenger side of the tank, including the vapor line and the larger supply line. These lines have connectors that you will need to squeeze at the base to release. Be prepared for some fuel spillage when disconnecting these lines, as there will still be some pressure left in the lines. Always wear safety goggles to protect your eyes from any gasoline splash.

By following these steps, you will be able to successfully and safely disconnect the fuel tank filler hose when changing the fuel pump on your 1999 Chevy 1500. Remember to take your time and work in a safe, well-ventilated area to avoid any potential hazards.

Disconnect fuel tank lines

To disconnect the fuel tank lines of your 1999 Chevy 1500, follow these steps:

Step 1: Move to the passenger side of the tank.

Step 2: Disconnect all the lines going into the top of the tank, starting with the vapor line. Pull it off from the charcoal overflow tank.

Step 3: Disconnect the larger supply line next. These two lines have a similar connector type. Squeeze at the base of the connection and pull the lines off with a little wiggle.

Note: When you remove these hoses, a lot of gas will spill from the lines as there will still be some pressure left. Make sure you wear safety goggles to protect your eyes from gasoline.

Step 4: There are two more lines above the vapor and supply lines that need to be disconnected as well. These will pop right off, but you'll need both hands as there are white connector clips that need to be pushed in simultaneously while pulling on the hose.

By following these steps, you will successfully disconnect the fuel tank lines on your 1999 Chevy 1500, preparing you for the next steps in the fuel pump replacement process. Remember to take necessary precautions when working with gasoline and always work in a well-ventilated area.

Disconnect power lines to the fuel pump

To disconnect the power lines to the fuel pump of a 1999 Chevy 1500, follow these steps:

First, relieve the fuel line pressure. Pull the fuel pump relay from the fuse box and start the vehicle. Let the vehicle run until it shuts down by itself. This will relieve the gas pressure in the line and the pump. Make sure you are working in a well-ventilated area, free of any heat sources, sparks, and open flames. Do not smoke while working around fuel sources.

Next, locate the power lines to the fuel pump. These are the two quick-release electrical plugs on top of the fuel tank that power the fuel pump. Simply disconnect these plugs from the pump.

Now that the power lines are disconnected, you can proceed with removing the fuel pump. But before that, you will need to remove the gas tank straps and lower the tank. Use a 15 mm socket and ratchet with a long extension to remove the straps. For the rear strap, you may need an assistant to hold the tank while you remove it, as it will be heavy. If you don't have an assistant, you can use a hydraulic floor jack to hold and lower the tank carefully.

Once the tank is lowered, you can proceed with cleaning around the fuel pump and removing any debris, leaves, or rust. After cleaning, disconnect the three lines from the fuel pump using quick-release clips. Squeeze the clips with one hand and pull the hose off with the other.

Now you can remove the fuel pump by turning the locking ring counter-clockwise. It should pop right up, and you can then fish it out from the top of the tank. Be slow and careful during this step, as more fuel will drain out.

After the fuel pump is removed, you can install the new one. Follow the manufacturer's instructions for any assembly required for the new fuel pump. Compare the new pump with the old one to ensure proper installation.

Finally, reinstall the fuel pump into the tank, reconnect the lines, and reinstall the gas tank. Reconnect the power plugs to the top of the fuel pump and the wiring harnesses. Reconnect the fuel lines and the filler neck, tightening the hose clamp and the vapor hose.

Keep the truck in the air while replacing the fuel pump relay and starting the engine. If there are any issues, you can easily access the fuel pump for further adjustments. If all goes well, lower the truck back to the ground, shut the hood, and take your Chevy for a test drive.

Remove gas tank straps and lower tank

To remove the gas tank straps and lower the tank, you will need a 15 mm socket and ratchet with a long extension. Start by removing the front strap completely. For the rear strap, you will need an assistant to hold the tank while you remove it. The tank will be heavy, so be careful not to let it crash down onto the floor. If you don't have a helper, you can use a hydraulic floor jack to hold the tank and then lower it carefully when the last strap is removed. It is recommended to have as empty of a fuel tank as possible to make this step easier.

The tank strap is held in place by a single 15 mm bolt. Once the straps are removed, carefully lower the tank with the help of your assistant or the hydraulic jack. Place the tank on the floor and clean around the fuel pump, removing any debris, leaves, or rust. You don't want any of that stuff falling into the tank.

Now, you can proceed to disconnect the three lines from the fuel pump. They are connected with quick-release clips. Squeeze in the clips with one hand and pull the hose off with the other. Once the hoses are off, turn the locking ring counter-clockwise and it should pop right up. Then, you can remove the entire module by pulling it up. The pump will drain more fuel when it's out, so go slowly and keep as much fuel in the tank as possible.

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