I purchased an all-in-one DMCH fuel pump module secondhand, so I can't verify if the hoses I have are original, although they probably are. Module was installed in fall of 2016.

Today I had my main feed hose slip off of the barb on the hardline. Luckily I was only a block from the car show I was just attending and did a quick field repair. Close inspection later revealed that the liner had softened, and because the K-jet hose barbs are a fairly smaller OD than the ID of these 5/16" hoses, the softening allowed the hose to slowly work off of the barb even with the FI clamp fully secured. Pieces of the hose had actually broken loose and the hose had to be trimmed slightly so it could be temporarily refit.

These are Gates hoses which appear to be resistant to modern fuels. Gates 4219BF specifically. The bottom hose section in this photo shows a series a marks
inside the hose. I was able to do this with my fingernail.

I personally dislike rubber fuel hose regardless of markings and will be working up a PTFE solution. I was able to easily build new temporary hoses using 5/16" fuel injection hose from Advance, but I suspect given enough time issue will occur again.

Defective-Gates-Hoses.jpg

So I guess the question is, are these the OEM hoses on the new fuel pump module? If so, they should be inspected.