This article was appropriately timed as I just finished up replacing fuel lines and installing a fuel cutoff valve. Fire is one of my biggest concerns with our bus; along with a major accident. While I cannot do much about the latter aside from careful driving, I can do a lot about fires or, rather, preventing them. According to most forum threads and conversations with enthusiasts, the most common cause of fires in old VWs (not just buses) is old, worn, brittle fuel lines.
Just over a year ago, I posted about modern fuels and fuel line options. In that post, I described replacing my braided-cloth lines with 30R07 hose; supposedly made of better material to withstand gasoline additives, in particular the ethanol that is used in the U.S. in ever increasing amounts. Around here, we have 10% (E10) ethanol but the amount varies depending on state. Ethanol is used to create cleaner burning fuels to reduce smog and other pollution, however, the sacrifice in using this additive is three fold. First, it reduces ignition temperature of gasoline and therefore the potential energy. Ethanol also attracts water which leads to storage issues when cars, lawn mowers, or other gas burning machines are left unused for as little as a few months. The water not only degrades the quality of the fuel and increases the potential for water slugs shutting down the engine, but also creates a perfect environment for rust in fuel tanks. If fuel tanks are not drained first, fuel stabilizers are recommended for any machines not used or left in storage. Lastly, ethanol permeates older rubber fuel lines causing them to dry out and become brittle faster; in some cases lines failed in less than a year.
The 30R07 lines I used, according the manufacturer, are designed for modern day fuel additives, including ethanol. While certainly not the highest rated out there, they are readily available at FLAPS and relatively inexpensive. I have heard much about how 30R07 lines are no good, but each advisement against using such line I saw at the time seemed to be based on the existence of higher rated fuel hoses rather than personal experience. With the interest of gaining experience, I decided to run my experiment of installing 30R07 from a quality manufacturer. A year later, here are the results (keep in mind that there are plenty of opinions out there on this subject. I am just throwing my personal experience out there as food for thought and not saying what I did is best for all).
In the end, I think a lot depends on what one’s goals are from the outset. If you need a less expensive hose for whatever reason, 30R07 will do just fine. It’s material strength adequately withstood the year long test (including a few months of storage with fuel stabilizer added) when compared to other hose types used in the past; perhaps outperforming the old style braided lines. While braided line tends to become stiff and prone to cracking, this line stayed supple and suffered no cracking at the ends. Integrity, at least within a year’s time, was not an issue for my line.
Unfortunately, in my opinion, 30R07 hose does have a major drawback. During the year, a faint gas odor in the garage was detectable. The odor strength varied from barely noticeable on cool days (although it was always strongest around the air scoops) to rather pungent after driving on hot summer days. This problem may be due to gas permeating through the hose walls since 30R07 line has a higher permeability (550g/m2/day) than 30R09 (15g/m2/day) or 30R14 lines.
The next step in this endeavor was to replace all the fuel lines once again, but this time using the highest rated hose available and the most recommended on classic car forums and by VW enthusiasts, Barricade 30R14 with GreenShield® technology (or here), an updated version of the older Gates 30R09 product. According to the manufacturer’s information, the permeation rate is significantly lower then 30R07 at around1-2g/m2/day. The results were immediate and noticeable without driving the bus! Even after running the engine for about half and hour while checking the timing and adjusting the carbs, there still was no fuel odor in the garage or near the air scoops. I got the bus out the following day, which proved warm and humid, changed the oil and headed down the road to find out if a long drive might produce an odor. After putting her back in the garage, the gas odor was still absent that evening, the next morning, and is still. We will see how the next year goes, but the new lines are off to a good start.