Replacing Rubber Fuel Fill Lines In 1999 F150s: A Step-By-Step Guide

If you notice that your Ford F-150 is leaking fuel, it may be time to replace the rubber fuel line. This is a charged line that delivers fuel from the tank through a filter and into the engine. Before you begin, make sure you have the necessary tools and safety equipment, including a new fuel line, hose clamps, a flat-head screwdriver, a 13mm ratchet with an extension, a lubricant, a bucket, safety goggles, and latex gloves. Working in a well-ventilated area, release the gas line pressure and drain the gas from the line to avoid spraying gas when you disconnect the line from the fittings.

Disconnect the fuel filter

Disconnecting the fuel filter on your 1999 F-150 requires a few tools and safety precautions. Before you begin, it's important to note that you should never perform this task with a hot engine, and you should always wear eye protection and avoid smoking while working on a fuel system.

• Release Fuel Pressure: Before disconnecting the fuel line, it is crucial to release the fuel pressure in the line. Locate the Schrader valve on the passenger-side fuel rail and depress it to depressurize the lines.
• Remove Safety Clip: Identify the safety clip on the end of the fuel line where it connects to the filter. Squeeze the clip together and unhook the small latch to remove it.
• Slide the Fuel Line Away: Once the safety clip is removed, slide the fuel line away from the filter to create enough space to insert a fuel line disconnect tool.
• Insert Fuel Line Disconnect Tool: Purchase or acquire a fuel line disconnect tool, such as a K-D 3321 or a similar tool. Insert the tool into the fuel line, pushing it away from the filter. You will hear or feel a click indicating that you have successfully disengaged the locking device from the filter.
• Pull the Fuel Line Away: After disengaging the locking device, carefully pull the fuel line away from the filter. Some fuel may start to drain out, so be prepared to control the spillage.
• Re-emphasize Safety: It is important to prioritize safety throughout the process. Ensure you are wearing eye protection and take precautions to minimize fuel leakage.
• Remove Fuel Line from Inlet: Repeat the process to remove the fuel line from the inlet side of the filter.
• Disconnect the Fuel Filter: At this point, the fuel filter should be completely disconnected and ready for removal.

Remember to exercise caution and follow safety guidelines when working on your vehicle's fuel system.

Remove the fuel rail bracket

To remove the fuel rail bracket, you will need the following tools:

• 13mm ratchet with extension
• Lubricant (e.g. WD-40)

Before you begin, ensure that you are working in a well-ventilated area, and that there are no open flames or heat sources nearby.

First, disconnect the fuel filter. You will need to purchase special disconnect clips or fabricate your own using a piece of plastic tubing (e.g. a marker cap) to disengage the safety clips in the coupler. Completely remove the filter from both ends of the line—caution: fuel may spray or leak out of the line.

Next, use the 13mm ratchet to remove the bolt that holds the fuel rail bracket onto the transmission. You may need to lubricate the bolt to help it break free. This will help with the tight space you have to do the rest of the work.

Cut the line off the pipe fitting

Before you cut the line off the pipe fitting, make sure you have the right tools for the job. You will need a new fuel filter, a 3/8" ID fuel-injected fuel hose, a 3-22mm midget pipe cutter, two fuel-injected hose clamps, a flat-head screwdriver, a 13mm ratchet with extension, lubricant (such as WD-40), a bucket, safety goggles, nitrile gloves, and shop rags. It is also important to ensure your truck is cooled off before you begin.

Now, let's get into the process of cutting the line off the pipe fitting. Start by disconnecting the fuel filter on the blue clip end. Be cautious, as some fuel may spray out, and ensure most of the fuel is drained out of the lines. Next, use the 13mm ratchet with an extension to remove the bolt that holds the fuel rail bracket onto the transmission. You may need to use some lubricant to help break the bolt loose. This step will give you more room to work on the fuel rail when cutting the line.

Get your midget pipe cutter and begin cutting the line off the pipe fitting. Cut right after the bend, as close to the end of the hose as possible. Be careful not to cut the pipe itself unless absolutely necessary.

Once the line is cut, you can move on to the next step of connecting the new fuel hose to the access pipe.

Connect the new fuel hose

To connect the new fuel hose, you will need a new fuel hose, two fuel-injected hose clamps, a flat-head screwdriver, and a bucket, safety goggles, and gloves for safety.

First, prepare your new fuel hose. It should be 3/8" in diameter and 2 feet long. You will also need two hose clamps that fit this size of the hose. Before you begin, ensure your truck is cooled off, and you are wearing eye protection and gloves.

Now, carefully insert the new hose over the access pipe, also known as the fuel rail. Secure the hose with the two hose clamps. Do not over-tighten the clamps, as this may cause them to break or cut the hose.

Next, attach the other end of the hose to the fuel filter. If you have a quick-disconnect coupler, insert it into the end of the new fuel line. If you do not have a quick-disconnect coupler, connect the fuel filter directly to the new line and secure it with another hose clamp.

Finally, re-attach the fuel rail bracket and route the hose away from the catalytic converter and exhaust pipes.

Attach the other end of the hose to the filter

To attach the other end of the hose to the filter, you will need to have a quick-disconnect coupler. Insert the coupler into the end of the new fuel line. If you do not have a quick-disconnect coupler, you can connect the fuel filter directly to the new line and secure it with a 3/8" fuel-injected hose clamp.

Bypassing the quick-disconnect coupler is said to make replacing the fuel filter easier in the future, without the need for special tools. However, it is not necessary to do so.

Make sure to route the hose away from the catalytic converter and exhaust pipes. Reattach the fuel rail bracket.

Now, cycle your engine from "Off" to "Run" and listen for the fuel pump and look for leaks. Carefully inspect all of the connections. If anything appears wrong, release the pressure from the lines and check your work. Re-tighten any loose connections and fix any errors.

Frequently asked questions