Other Any Rubberologists out there??

Identified these failing diesel hoses whilst doing another job. They were below the fuel pump on a 2002 TD4 so inside the front wheel arch area.

I thought it was rodent damage but my wife says not. Some pipes in the same route were in perfect condition and these were very badly pitted and quite weak in spots.


Anyone know what is the cause?

I can guess at oxidation of the rubber. I've seen old brake hoses suffer in a similar way.