My Harley is leaking gas through the tank hose. How do I fix it?

• Ethanol is much more corrosive than gasoline: it can affect soft parts in carburetors, injectors, and other fuel system components if the vehicle is not prepared.
• Ethanol should not be stored with the vehicle stopped for too long, as it creates varnish very easily and can cause system malfunctions.

That said, remember that the current percentage allowed by law is very low, so we generally won't encounter problems of this type.

The problem
Although the specific cause has not been proven, it is a fact that in recent years, motorcycle fuel system failures have been occurring due to corrosion in O-rings, which, when degraded, lose their sealing capacity.
A specific example is the fuel inlet on Harley-Davidson motorcycles with fuel injection. This quick-disconnect fitting is subject to pressure from the fuel pump, vibrations (it connects a fixed part, the frame, to a "moving" part, the engine), and extreme heat due to its proximity to the cylinder heads. These conditions (and perhaps the composition of new fuels) cause damage to the O-rings, leading to the typical fuel loss.

Options
Normally, repairing this leak involves replacing the fuel tank's high-pressure intake , a fairly expensive option due to the cost of the components and the labor required for the operation.

An American company called Fuel Tool (in the US, ethanol blends are even higher) has created an inexpensive repair kit that allows us to restore and improve the fuel intake, as it uses Viton seals, which are highly resistant to corrosion.

As can be seen in the photograph, the kit manufacturer also provides a set of repair tools .

Disassembly
We're going to repair a leaking fuel inlet. We'll start by emptying the tank, then remove the fuel injection fuse and try to start the bike. This depressurizes the system. We can now disconnect the quick connect by pushing the lock upward.

We will now use the hook and the extraction tool marked “A”.

After inserting the tool and turning it, we will see that it “pierces” the lower O-ring and we can now remove it.

We repeat the operation with tool “B”, thus removing the upper O-ring and the safety valve, which we will also replace.

Mounting
After making sure that everything is perfectly clean, we will lubricate the new seals and valve with a little specific oil and insert them into the installation tool,

After which we will gently push the installer's plunger until we hear a "click" that will indicate that everything is in place.

The final step is to install the lower O-ring, again using tool “A”.

Testing
Once the assembly is complete, we can reconnect the hose and refill the fuel tank. We'll start the bike and check for leaks or friction between the components.
As a final check, we can perform a test with the fuel pressure tester , which will allow us to simultaneously determine the status of the pump and the pressure regulator. The pressure should be constant at any throttle position and between 50 and 60 psi.

Problem solved, we can now go out riding, and we've achieved it in approximately one-third of the time and expense of traditional replacement.

Frank Burguera

#harleymechanics