Replacing the fuel lines

Click here for the year after update!

A few weekends ago, I finally got around to replacing the fuel lines on Moby.  I say finally  because it was on the to-do list for 9 months now but since the old rubber lines seemed just fine, replacement did not become a priority.  Last fall, when I changed the fuel filter, a fuel line cracked at its end; a warning of impending failure for the rest of the hoses and pushed this project up on the list.  In the past, replacing fuel lines was never an issue so long as one bought quality line, usually German made braided fuel hose.  In fact, it was a job I never gave much thought about and would reuse pieces of line on a regular basis if I could bend them in half without breaking them.  As the ends got brittle, I would simply snip them off, reattach and be on my merry way.

In the intervening years since I worked on VWs I, of course, did not keep up with who made or sold good fuel hose and what alternatives existed.  So I decided to do a little research and found replacement is no longer so simple!  This might be mostly due to the fact I read way too many stories regarding buses going up in flames after fuel lines fail.  These stories got me thinking about the facts that Moby cost four times the price of any other bus I owned of the years and, more importantly, now carries two miniature VW enthusiasts; a cargo more precious than I ever transported before.  Opinions on what line is best vary widely as does the experiences everyone seemed to have with various manufacturers.

Turns out the old stand by German fuel lines may, according to some, be susceptible to quick failure when exposed to modern ethanol fuels.  While some state they get only a few months out their lines others claim up to two years before replacement is necessary; a fairly big discrepancy.  It also seems that Germany is not the only producer of braided fuel hose and one must also account for these cheaper versions sold without identifying country of origin or, in some cases, “mislabeled” made in Germany.  One might solve these issues with a trusted vendor but some people swear their faulty lines came from quality sources.  OK then, what are the alternatives if Old Reliable is not so, well, reliable anymore?

This question plunges one into a plethora of opinion and controversy; can there be no simple solutions?  If money is not an object, steel fuel line and their accompanying fittings solve the issues of ethanol and cracked rubber ends.  Too bad money is an object for me!  The top choice of most online threads seems to be fuel line rated SAE J30R9, which is ethanol resistant and therefore solves the problems with the rubber drying out.  The down side of this type of hose is that it only comes in 1/4 inch as its smallest I.D.; just a hair bigger than the stock metric fuel line I.D. (after replacement, I did find 5.6 mm 30R09 fuel injection line sold in Europe for ~$50/5 meters). I have used 1/4 inch lines on past buses, mostly because of beefier fuel filters required to remove gargantuan amounts of rust bits and was never happy with its fit.  Because the line is a tad bit bigger than stock size, the hose clamps must be torqued down until they bite into the rubber line and even then the hose tends to rotate on their fittings.  While they never leaked, I was always a bit leery of them popping off.

Another alternative is hose rate SAE 30R07, which appears to be ethanol resistant (550g/m2/day) but not quite to the point of the 30R09 stuff (15g/m2/day).  The plus of 30R07 line for me is that it comes in 3/16 inch which is just a hair smaller than the original metric lines.  After going back and forth between these two line types, I settled on a 3/16-inch 30R07 made by Goodyear because I have greater faith in the tighter fit and hope that the 07 rated would last as long as the good quality braided line.  It was also cheap enough for this experiment so I will not be too heartbroken if it fails in a month or so.  I will post updates as the experiment progresses but so far so good!  In the mean time I will keep the European metric 30r09 line in mind for experiment #2.

The old line. Definitely time to swap it out! The one welded itself on to the carb fitting.

The new fuel line. (click to enlarge to read the fine print)


One thought on “Replacing the fuel lines

  1. Pingback: Replacing fuel lines update – A year later | Zero to Sixty . . .Eventually

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