Fuel Lines

August 9th, 2010 by Galen Bowen Leave a reply »

Senior Mechanical Engineer

I have a Toyota Landcruiser that is a never-ending project.  I bought it with a blown motor, and put in a Chevy 6.2l diesel, as this seemed the easiest and cheapest diesel swap.  (Got the motor out of a van I bought for $600.)  From that point, I went to a Mercedes OM606 (not enough power with the non-turbo’d version), then to a Mercedes OM617 (I think this is my favorite diesel engine of all time, but still 2998 cu cm is a bit small for hauling around a 5,000 lb FJ-60).  My current motor is a Cummins/Onan L634T.  I’ve pretty well burnt myself out on motor swaps, so I intend to stick with this one for a while.

I never really gave much thought to biodiesel resistant fuel-hoses back when I was changing my engines more regularly than I was changing my oil.  By the time my fuel hoses began to degrade, I’d be tearing them out anyway to plumb the fuel to a different motor.  However, since I’ve actually stuck with my current motor for a couple of consecutive years now, I’ve been forced to confront this gooey issue:

Gooey Fuel Line

This picture is actually from my brother’s car (he obviously is not a great deal more fastidious in this regard than I am.)  I never got a photo of the fuel lines in my truck, but they looked about the same.

I figured I’d have to order some kind of special Viton tubing from McMaster Carr at $8/foot if I would ever by rid of the above pictured phenomenon.  However, while doing some research on an excellent VW TDI forum (www.tdiclub.com), about an issue with my wife’s Passat, I noticed a thread about biodiesel resistant fuel hoses.  Turns out it’s common knowledge over there that there is a standard fuel hose available which is biodiesel resistant.  It’s SAE 30R9, and it has a flouroelastomer liner.  It’s more expensive than the regular stuff you normally buy (SAE 30R7) but it’s a lot less than buying viton tubing, it’s a lot tougher since it’s actually a reinforced hose, not just a tube, and best of all, you can get it from a typical auto parts store.   They guys behind the counter usually know it has ‘fuel injection hose,’ or ‘high pressure fuel hose’ since it’s got a higher pressure rating than the SAE 30R7.  For 5/16”, it’s usually $3-4/foot.

SAE 30R9

For the first time in a long time, my truck is not a ticking time bomb waiting to spew biodiesel all over my engine compartment from a hose which has degraded into rubber putty.

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