the one guy had said nylon line(a long post ago, and early in this topic). use only fuel rated hose.
i have a length of this tygothane from mcmaster. i have for inlet and the inbetween injector over-flows used for me on older idi's. it wasnt long before the larger inlet hose turned a yellow and got cracky, not really too much problem, after several years just sitting, they still work, are ok. for me as well an observation. its somewhat expensive line. my main problem, when first setting up, the wall thickness is rather thin, my hose clamps that take wrench or socket(1/4") or screwdriver, can and at first did rather easily bite thru the lines where clamped. its kind of testy material, if you dont tighten the clamp right, you will get a leak where you have to tighten more, biting thru hose. i have to tighten over the filter the nipple lip, and snug clamp so it works.
the inbetween injector lines, i find useful, in my old idi's are real testy, zip-ties can work here. otherwise i ll get #3 leaking, usually, can be another.
as a suggestion where you can use rubber fuel line, use fuel injection line. on another forum at least one newer member some how was under the impression to use fuel (non-injection line, hence carburetor fuel line)line. carb fuel line you cannt use for injection line/hose, injection hose you can use for anything fuel line, that we d use it for. just pointing that out.
was thinking of any type of fuel rated clear line as long as it can handle diesel, for us. thicker wall thickness id prefer.
as far a prev poster, except for my comments observations, and others, for our car, VW purposes most times for inlet line and return line(s), your ok, unless you personally have heat requirements for what your doing. if your running your fuel lines right, that sounds normal, fuel runs cool. you ll set up and 'tie down' in a cool spot.
