DIY: Fuel line repair! No more cold weather fuel smells! (04-08 Fxt)
If your Subaru resides in a climate prone to sub freezing weather you may have experienced this issue. If not lets discuss what and why this happens. With time comes degradation and on the Subaru fuel system time and temperature will cause a leak. Freezing temps causes the factory rubber fuel lines to shrink which in turn leaks out on to the engine causing a terrible fuel smell. This, under the wrong circumstances could cause a fire.. if the fumes that seep into the the cabin can give you an awful headache and difficulty driving your vehicle.
Ninety five percentage of the Forester's factory fuel lines are hard metal lines. With the last five percentage being rubber line connections that run under the intake manifold, another on the outside of the intake manifold near the fuel pressure regulator and and behind the A/C compressor. The most likely and difficult culprit of the fuel smell/leak is the two rubber lines that run under the turbo inlet. Removal of the intake manifold is necessary and I will link it shortly when the diy is completed.
Let's get down to the tools needed. We will need a razor blade, a pair of pliers and a screwdriver. You will need additional hoses replacement. You can reuse the factory hose clamps or replace them as well. 5/16” fuel injection hose 5/16” hose clamps 10 pack linked on Amazon. A few other tools that can be of help. Hose remover pliers, Fuel line disconnect tools and Gates hose cutter tool .
Most of the images below will show the hard fuel lines off of the intake manifold. This is not necessary but for an easier viewing DIY and the ability to paint the intake manifold, I went ahead with this method. With that being said I have many images like the one below that will show you where the lines sit on the manifold.
We will start with the two lower hoses under the turbo inlet. These are the most common for leaking and what should be your first step. After locating these two hoses, then remove the clamps for the ends of the hoses. Now take your razor blade to the hose cut a slit on both sides of the hose, this will allow for easy removal of the hose. As you may have noticed, they have become hard and brittle. This is exactly the reason why they leak. The hose has become so brittle that the clamp no longer puts enough force upon it to keep the fuel from leaking out. So let’s get our new hoses cut, placed on the hardlines and tightened down.
With the fuel lines cut you may now set them next to your new lines and measure out new hoses. Using your razor blade or hose cutter, you can now chop them to length and begin to slide them on to the hard lines. Making sure that the clamps were installed on the rubber hoses before pushing them over the hard line. You can decide which way the clamps sit on the hard lines, making sure that they do not interfere with the turbo inlet. I tried to install them in such a way that they can be re tightened after the intake manifold is installed but this doesn’t work. I would recommend installing them in the best manner you can or following how the factory installed them.
Now that the hoses are on in the clamps have been tightened down I recommend to tighten the clamps as much as possible. If you are at a stopping point this is a good time, take an hour break and then return to tighten them down once again. Allowing for time in between tightening the clamps fully, will help the rubber except the clamping force. if you have the ability to leave them overnight and retighten them this would be a great practice, allows the rubber to expand and except a clamp.
You may now begin on either of the other lines. The line I completed next was that 1 located near the fuel pressure regulator. This line needs to be precisely cut in the length of the removed line. If not the bunched up hose could cause a fuel blockage. I haven't seen any documented failures of this hoses but I went ahead and replaced it. This is the easiest hose to reach when the intake manifold is installed. It could be left on and replaced at a later time without intake manifold removal. Tighten up the hose clamps and you are complete with a another line.
The last hose to go is the one that sits behind the A/c compressor. If you remove the A/c compressor you can easily replace the hose with the manifold on the car. But once again if you have it off, why not take the time replace it and forget about it. This hose started leaking shortly after I fixed the two hoses under the turbo inlet. Using your favorite technique to remove this hose, with prior taken measurements you can cut your last line. Sliding it over both sides of the hardlines you can install the clamps and finish your task.
At this time I would remind you to retighten every hose clamps once more for a final check before reinstalling it into the car. The time spent double checking these clamps is a worth while investment. If you have to remove the intake manifold you will think to yourself… why didn’t I recheck them!?! I had to redo this task twice because I was sold the wrong clamps by the parts store. Now matter how tight they were turned they still leaked.
Congratulations! You have repaired your leaky fuel lines. Hopefully they will stay in the hoses and not return to your interior of your car or your nostrils.