I thought this might be a subject of general applicability, so I'm putting it in OT.
Flexible Fuel Hoses need to be replaced periodically in old cars (just like rubber brake hoses), but I'm not sure how often...
Other factors are whether the fuel hose is rated for the newer fuels (which contain Et-OH, ethanol) and the pressure they have to withstand. All these factors are things that the guys who work in auto parts houses seem NOT to understand (along with what clamps to use, but I'll get to that later).
I bought a VW Vanagon a couple of years ago (
http://forums.pelicanparts.com/off-topic-discussions/465200-slow-going.html), and this vehicle seems unusually susceptible to engine fires. I'm not sure if the risk of an engine fire in an old 911 is just as high, but my '73 DOES have the stupid design of putting the fuel lines near all the electronics -- like the high voltage sparkin' machine to make the spark plugs explode the fuel...
So, I've been trying to figure out what fuel lines to put on der Vanergon. One thing seems consistently and insistently mentioned on VW Vanagon forums is to use a rubber hose that is rated for Et-OH fuels. SAE has a spec for that: SAE J30R9.
AutoZone claims that they have FI hose from Goodyear rated J30R9, so I went there (actually I went there 3 times, and also went all over this town to every LAPS - and now believe that none of them is my FLAPS). I finally got the robotized humanoids at Autozone to find their hose, and it was not Goodyear.
Their hose DOES have SAE J30R9 stamped on it, but says the brand is "ArmorMark" and that it is made in Thailand. It also says WP 6.9 bar (not sure what WP means, but I assume it is rated to 6.9 bar, which just happens to be approximately
5,175 torr {or a tad over 100 psi fer y'all Anglais system folks}).
Now, people have posted on der Samba Vanagon forum about the Et-OH compatible hose having an internal liner (which used to be blue then changed to a black color). I cut this hose open and it does NOT have a liner, even a black one.
So, I thought I would post this to see what people here thought. Maybe someone on here is an expert in fuel hoses...