Rubber hoses / ULSD

[Shikaroka]

All of the injector install kits I have seen come with the older style fabric and rubber return lines. Are these suitable to use with ULSD fuel or should they be replaced with some Viton (synthetic rubber) hoses? Where is a good source for some good quality hoses?

[DmaxMaverick]

ULSD should have no additional effect on return lines. The fuel is still #2 with no additional additives harmful to the rubber return lines. The OEM style hoses are good, and better than most aftermarkets. www.kennedydiesel.com has a quality, complete set. A Viton upgrade would be OK, but not necessary if you aren't running bio/VO.

[Shikaroka]

I have heard of the new ULSD fuel cause leaks in rubber seals in older diesels, so I was just curious about the hoses for the 6.5td.

[DmaxMaverick]

I would attribute that to coincidence, and ULSD would be an easy scape goat. Same thing happened back in '93 when we went to 500 PPM fuel. There were some issues with lubricity, but, "that new fuel is leaking all over" was used handily. Problem is, most of the leaks were there before. Rumors and hyped media coverage made folks look for leaks, and they found them. I suspect we will be having a replay of 14 years ago.

[Shikaroka]

Yeh, I agree, but even Standyne says that ULSD fuel can cause rubber seals to shrink and possibly leak.

[DmaxMaverick]

Yeh, I agree, but even Standyne says that ULSD fuel can cause rubber seals to shrink and possibly leak.

It has to be a direct relation to the lower lubricity, not chemical. This only applies to dynamic seals and wear parts. Hoses and gaskets are completely uneffected.

[Shikaroka]

From here:
http://www.stanadyne.com/new/ppt/showfile.asp?id=3437

"− Fuel System leaks. Reducing sulfur also
reduces aromatics. This can result in rubber
seals an hoses in some fuel system
components shrinking and resulting in fuel
leaks. NOTE: Stanadyne fuel systems do not
use natural rubber seals but use Viton