Replacing Fuel Pump On Short Block Chevy: Step-By-Step Guide

Replacing the fuel pump on a short block Chevy engine is a complex process that requires careful attention to detail. The fuel pump is located on the passenger side front corner of the engine, in front of the motor mount. While the process may vary slightly depending on the Chevy model and year, the basic steps involve removing the fuel lines, disconnecting the pump, addressing the fuel pump push rod, installing the new pump, and ensuring proper gasket placement and lubrication. It is important to take precautions when working with fuel and to be aware of potential challenges, such as the push rod falling or sliding down during the process.

The fuel pump is located on the passenger side front corner of the engine

To replace the fuel pump, you will need to remove the metal fuel line. Use a 5/8" line wrench to do this. Be prepared for some fuel to leak, so wrap a rag around the wrench and flare nut to catch it. You should also ensure that no one is smoking or welding nearby. It is important not to bend the metal line, even slightly. Once the flare nut is removed, slide it back and do not pull the metal line out of the fuel pump fitting. Instead, remove the rubber fuel line from the pump and plug the fuel line to prevent leaking.

Next, you will need to remove the fuel pump flange bolts. These bolts can vary in size, so be prepared with different sized tools. It is recommended to loosen both bolts and then alternate between them until they are out. You will also need to remove the fuel pump backing plate to access the fuel pump push rod.

Now you can install the new fuel pump. Clean the parts and use a thick grease to lightly coat the fuel pump push rod. This will prevent the push rod from falling out. Clean any remaining gasket from the engine block and fuel pump backing plate, and glue a new gasket to the back of the fuel pump backing plate. Use a solvent and a rag to ensure all parts are grease-free before gluing.

Finally, place the fuel pump backing plate in position and start all four bolts in their respective holes. Tighten the two small bolts at the bottom of the plate before removing the two fuel pump bolts. This will ensure the fuel pump backing plate is properly aligned.

Follow these steps and you will be well on your way to successfully replacing the fuel pump on the passenger side front corner of your Chevy small block engine.

Use a 5/8 line wrench to remove the metal fuel line

To replace the fuel pump on a short block Chevy, you'll need to remove the metal fuel line using a 5/8" line wrench. Here's a step-by-step guide to help you through the process:

First, locate the metal fuel line. On a Chevy small block engine, the fuel pump is located on the passenger side front corner of the engine, immediately in front of the motor mount. Identify the metal fuel line connected to the fuel pump. It's important to note that the fuel line may be pressurized with fuel, so be prepared for potential leaks. Have a rag handy to catch any leaking fuel, and ensure that there is no smoking or open flames nearby.

Now, let's focus on the removal process. When using the 5/8" line wrench, be gentle and do not apply excessive force. You only need to loosen the flare nut connection at the fuel pump. Avoid removing the flare nut connection at the carburetor. Once the flare nut is loosened, slide it back, but be careful not to pull or bend the metal line. This is crucial to ensure that you won't have difficulty starting the threads when it's time to reinstall the new fuel pump.

At this point, you should also remove the rubber fuel line from the pump. It's important to plug the fuel line to prevent any further leakage. You can use the butt end of a drill bit or a similar object for this purpose. Additionally, check the valves in the fuel pump to ensure that no fuel drains onto the floor.

Now that the metal fuel line is disconnected, you can proceed with the next steps in replacing the fuel pump. Remember to refer to a comprehensive guide for the full procedure, as there are additional steps and precautions to take.

Safety is a top priority when working on your Chevy's fuel system. Always take the necessary precautions to avoid any hazards associated with fuel leakage and open flames.

Remove the rubber fuel line from the pump and plug the line

To remove the rubber fuel line from the pump and plug the line, you will need to be cautious and prepared. The fuel line may be pressurized with fuel, so be ready to catch any leaking fuel with a rag. Do not smoke while performing this task, and ensure no one nearby is welding or using a flame.

Use a 5/8" line wrench to remove the rubber fuel line from the pump. You can wrap a rag around the wrench to capture any leaking fuel. Once the line is removed, plug the line with something to prevent fuel leakage. You can use the butt end of a drill bit, for instance. The fuel supply line can be 5/16" or 3/8".

It is important not to bend the metal line, even slightly. If you force it to come out, it could bend, and you will have difficulty starting the threads when it is time to reinstall the new fuel pump.

After plugging the line, you can proceed to remove the fuel pump flange bolts. On classic Chevy small block fuel pumps, the line wrench size for removing the flare nut is typically 1/2". The bolts on the fuel pump flange can vary, so be prepared to use different sizes. In the example provided, the bolts are 7/16", but they can also be 9/16".

Loosen both bolts, then alternate between them until they are both out. Be cautious when removing the bolts, as you will need to manage the tension of the fuel pump arm. The fuel pump arm on the backside of the fuel pump is driven by a push rod, which can fall or slide down when you remove the pump. This can present a challenge when installing the replacement pump.

To manage the push rod during the removal process, you can try the following techniques:

• Use a blob of clean chassis grease on the end of the rod to hold it in place temporarily while you get the pump out.
• Use a hack saw blade to push the rod up. Bend the last 4 inches of a new blade that has never cut metal. Push the rod up with your finger, and hold it in place with the blade while you install the pump. Remove the blade once the arm is placed on the rod properly.
• Use a feeler gauge to slip underneath the fuel pump rod. Once the pump is in position, slip out the gauge and bolt things down.
• Loop 18-gauge electrical wire around the rod and hold tension straight up as you remove the pump. Then, release one end of the wire and pull it out before tightening the bolts.
• Apply heavy grease to the pushrod to slow it down as it tries to fall out.
• Rotate the engine so the pushrod goes up to its highest point, making it easier to position the arm of the new pump.

By following these steps, you can safely and effectively remove the rubber fuel line from the pump, plug the line, and manage the push rod during the fuel pump replacement process for a short block Chevy engine.

Use a socket, ratchet and extension to remove the fuel pump flange bolts

To remove the fuel pump flange bolts of a Chevy small block fuel pump, you will need a socket, ratchet and extension. The bolts on this type of fuel pump are typically 7/16", but it's not uncommon for them to be 9/16" if they have been replaced. The bolt size is a 3/8" course thread.

When removing the bolts, it is important to loosen both bolts before removing either. Start by loosening each bolt a few turns, then alternate between them until they are both out. This will ensure that you do not completely remove one bolt before the other.

Once the bolts are removed, you can take out the fuel pump. Be aware that the fuel pump arm is driven by a push rod, which will fall or slide down behind the fuel pump backing plate. This can make installing the replacement pump more challenging.

Before installing the new pump, clean the parts and lightly coat the fuel pump push rod with a thick grease. This will prevent the push rod from falling out. You can then insert the push rod into the hole until it reaches the cam shaft and cannot go any further. Do not use a hammer to force it in.

Next, clean any remaining gasket from the engine block and fuel pump backing plate. Apply glue to the new gasket and place it onto the back of the fuel pump backing plate. Use a solvent and a rag to ensure that all parts are grease-free before gluing. After gluing the gasket, apply a thin layer of automotive silicone to the gasket surface.

Finally, place the fuel pump backing plate onto the engine block and insert the bolts into their respective holes. Tighten the bolts, starting with the two small ones at the bottom of the plate, before removing the fuel pump bolts. By starting all the bolts before tightening, you ensure that the fuel pump backing plate is properly aligned.

Grease the fuel pump push rod to prevent it from falling out

When replacing the fuel pump on a short-block Chevy, one of the key steps is greasing the fuel pump push rod to prevent it from falling out during installation. This process can be tricky, and there are several methods that can be used to achieve this.

Firstly, it is important to choose the right type of grease. A thick grease should be used, and only a small amount is needed to coat the fuel pump push rod. This will ensure that the rod stays in place without making it too slippery. In some cases, "Lucas Red n Tacky" grease has been used for this purpose. While grease is a common method, some people prefer to use alternative methods, such as the "bolt method", which involves removing the short bolt in the front of the block and installing a longer bolt to hold the rod in place during pump installation.

When applying the grease, it is important to be careful and deliberate. One technique is to use your finger to hold the rod in place while sliding the pump into position. This method requires installing the pump under spring pressure, but it can be quicker than using additional tools. Another approach is to use a thin tool, such as a screwdriver, a hacksaw blade, or a feeler gauge, to lift the rod and then hold it in place while applying the grease. If the grease makes the rod too slippery, you can try cleaning it off with a rag soaked in a small amount of gas before attempting to lift the rod again.

In some cases, you may need to get creative to lift the rod. One innovative solution is to use a piece of welding or brazing rod bent into an "S" shape with a hook on one end to catch and lift the pump rod. Another option is to use a loop of string to lift the rod, allowing you to pull it tight once the bolts are started. These methods demonstrate the ingenuity and resourcefulness of mechanics when faced with challenging tasks.

By following these steps and choosing the method that works best for your specific situation, you can successfully grease the fuel pump push rod and prevent it from falling out during the replacement process for a short-block Chevy.

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