Fuel lines and fuel hoses are often inconspicuous under the hood of our vehicles, though they are vital components responsible for delivering fuel from the tank to the engine. Ensuring that the fuel system functions properly is crucial for a vehicle’s performance and safety. Unfortunately, fuel hoses are not immune to wear and tear, and when they fail, it can lead to a host of problems. First, you can experience reduced performance then, you could enter the realm of potential safety hazards and expensive repairs. In this blog, we’ll explore the following:
- Understanding What Causes Fuel Lines to Fail
- Recognizing Signs of Fuel Hose Failure
- Preventing Fuel Hose Failure
- What Type of Fuel Lines & Fuel Hoses Should You Use?
Understanding What Causes Fuel Lines & Fuel Hoses to Fail
The primary causes of fuel line and fuel hose failure are numerous, and they include:
- Misapplication: Using the wrong type of hose for a particular fuel or application.
- Kinking near fuel line fittings: Excessive bending and crimping near hose fittings can lead to restricted fuel flow and structural damage.
- Temperature Extremes: Exposure to high heat or freezing cold can weaken hose materials.
- Surging Pressure: Rapid pressure changes can cause hoses to weaken and rupture.
- External Damage: Physical impacts, abrasive surfaces, or chemical exposure can lead to hose damage.
- Inadequate Bend Radius: Hose bending beyond its recommended radius can cause kinking and structural stress.
- Defective Hoses or Improperly Selected Clamps: Using low-quality hoses or mismatched clamps can lead to premature failure.
- Incompatible Materials: Fuel hoses must be compatible with the type of fuel they carry to prevent degradation.
- Incorrect Hose Length: Incorrectly sized hoses may twist, kink, or strain, leading to damage.
- Twisting During Installation: Improper hose installation, such as twisting during fitting, can create weak points.
- Transfer of Contaminated Media: Contaminants in the fuel can accelerate hose deterioration.
Age, improper installation, and lack of maintenance can also contribute to hose deterioration. Similarly, contaminants in the fuel can exacerbate hose degradation.
Recognizing Signs of Fuel Hose Failure
Fuel lines & fuel hoses will often show these indications of failure:
- Fuel Odors: A strong gasoline odor clearly indicates a fuel leak and a significant safety concern.
- Visible Cracks or Leaks: Since a fuel hose leak may start slowly and be almost unnoticeable, it is crucial to inspect lines and hoses closely for visible cracks, bulges, or signs of leakage.
- Reduced Fuel Efficiency: Decreased fuel efficiency may signify fuel hose issues.
Preventing Fuel Hose Failure
Preventing fuel lines & fuel hoses from failing requires a proactive approach:
- Regular Inspection: Regularly inspect your vehicle’s fuel hoses during maintenance to identify early signs of wear or damage.
- Use Quality Hoses: Invest in high-quality hoses designed for fuel applications.
- Proper Installation: Follow manufacturer guidelines for hose installation to prevent excessive bending, twisting, or tension.
- Protective Shields and Covers: Consider protective shields and abrasion-resistant covers for hoses exposed to potential damage.
What Type of Fuel Lines & Fuel Hoses Should You Use?
Fuel lines and fuel hoses come in a variety of materials, including metal, rubber, braided nylon, braided steel, PTFE-lined, or plastic. When considering the right choice, especially for racing purposes, it’s essential to consult the rule book for your track or sanctioning body. Undoubtedly, selecting the appropriate material from the outset can help you save time, and money, and prevent future headaches.
Metal Lines
Presently, most factory-fitted fuel lines are constructed from metal, known for its superior durability compared to softer materials. These metal lines are typically made from stainless steel, aluminum, or coated steel tubing. While metal is considered the optimal material for fuel lines, it can be challenging to work with due to its rigidity.
Rubber Hose
Rubber fuel hoses are renowned for their ease of installation, typically connected using standard barbed fittings and fuel line hose clamps. It’s crucial to ensure that the rubber hose is rated for fuel and complies with specific SAE grades:
- SAE J30R7 is suitable for carburetor-rated fuel hoses, suitable for limited runs up to 50 psi.
- SAE J30R9 is designed for fuel injection and can withstand up to 100 PSI pressures.
Braided Nylon Hose
A braided hose is essentially a rubber hose with an exterior layer of braided stainless steel or braided nylon. It utilizes a hose end for connecting with the rest of the fuel system. While it offers greater durability compared to plain rubber hoses, it shares some of the longevity and fuel vapor issues associated with rubber hoses.
Nylon Double Braided Stainless Steel E85 Hose
The nylon double-braided stainless steel fuel hose for E85 fuel is highly durable and flexible, featuring a nylon outer braid and stainless steel inner braid for maximum strength. It’s resistant to abrasion and corrosion, ensuring longevity. Compatible with E85 fuel, it offers excellent fuel permeability, reduced wear, and increased safety, making it ideal for high-performance automotive applications.
If you’ve ever thought about converting your vehicle’s fuel system to E85, please consult our guides to make sure you’ve considered all the facts.
- FAQ: Convert to E85 Fuel and What You Need to Know
- What’s in Your Tank? Learn How Ethanol and Other Fuels Impact Your Fuel System
PTFE-Lined Hose
PTFE-lined hose is the preferred choice for flexible hose applications and typically features a braided stainless steel or braided nylon exterior. The PTFE liner effectively prevents fuel vapors and retards the degradation process. However, it’s important to note that PTFE braided hoses necessitate the use of special fittings and cannot be paired with standard AN fittings. Additionally, they are less flexible than conventional braided or rubber hoses.
Corrugated Flex Hose
Lastly, plastic corrugated fuel hoses offer advantages such as lightweight construction, corrosion resistance, flexibility, and cost-effectiveness. Their durability and resistance to environmental factors make them a practical choice for various applications. Additionally, their smooth interior minimizes condensation and eases maintenance. However, the suitability of plastic corrugated hoses depends on the specific requirements of the application, including the type of fuel and operating conditions.
Quantum Fuel Systems Has Your Back
Fuel hose failure in an automotive system is more than just an inconvenience; it’s a safety concern that can lead to performance issues and costly repairs. Understanding the root causes, recognizing the warning signs, and proactively addressing these issues are critical to maintaining a smooth and safe driving experience. We also sell fuel line fittings as well.
Regular maintenance, high-quality hoses, proper installation, and protective measures are key to preventing fuel hose failure and keeping your vehicle running smoothly on the road.
Frequently Asked Questions
Fuel lines and hoses transport fuel from the tank to the engine. They must maintain consistent flow under pressure, resist heat, and prevent leaks. When they fail, performance issues, fuel loss, or safety hazards like fires can occur, making their reliability critical.
Common causes include using the wrong hose material, kinking, heat or freezing, pressure surges, external damage, and poor installation. Age and exposure to ethanol fuels also weaken hoses. Choosing compatible, high-quality hoses and proper installation reduces the risk of premature failure.
Warning signs include strong fuel odors, visible cracks, leaks, bulging areas, or reduced fuel efficiency. Any smell of gasoline should be taken seriously, as it indicates a potential leak and fire hazard. Regular inspections help catch issues early.
Prevent failure by inspecting hoses regularly, using only fuel-rated hoses, following correct installation practices, and adding protective shields where needed. High-quality hoses and clamps ensure secure connections and prevent damage from abrasion or heat.
Fuel hoses can be made of metal, rubber, braided nylon, braided stainless steel, PTFE-lined composites, or corrugated plastic. Each has different durability, flexibility, and compatibility with fuels like gasoline or ethanol blends.
Rubber hoses are easy to install and affordable but must meet SAE fuel ratings. SAE J30R7 handles carbureted systems up to 50 PSI, while J30R9 is designed for modern fuel injection up to 100 PSI. Properly rated rubber hoses are reliable when used correctly.
Braided nylon or stainless steel hoses add durability and abrasion resistance compared to plain rubber. They are popular in performance builds but still share some limitations, like fuel vapor permeability, unless PTFE-lined versions are chosen.
PTFE-lined hoses resist fuel vapors, ethanol corrosion, and degradation better than rubber. They’re ideal for modern performance builds and E85 applications. However, they require special fittings and are less flexible, making installation more complex.
Metal fuel lines, typically stainless steel or aluminum, are highly durable and resist heat and abrasion. They are factory-standard in most vehicles but can be harder to work with due to rigidity. They’re best for long, straight runs.
Select a hose rated for your fuel type and pressure, with materials suited to your environment. For racing or ethanol fuels, PTFE-lined or braided stainless options are best. Always follow manufacturer and sanctioning body guidelines.
Thank you for highlighting recurring issues with corrugated hoses in our Harley Davidson fuel tanks. We recognize the significance of maintaining hose integrity for safety and performance.
The symptoms you described – brittleness, breakage due to vibration and shock, and discoloration – may be linked to ethanol in gasoline.
Ethanol would definitely be the cause of the symptoms you mentioned. Message me @ support@highflowfuel.com and we can discuss what I can do for you. Ask for Joseph
We have experienced multiple failures with corrugated flexible hose. Hoses are so brittle that they break due to vibration and shock. They are discolored and appear medium to dark brown.
I would assume this is due to ethanol content of gasoline.
Application is in Harley Davidson fuel tanks.
Any suggestions?