Recently changed drivers inlet manifold fo new , but twice I've had to sort the fuel return lines at the injector ports. I don't know if this is something I am doing wrong but maybe the small o rings have hardened.

Has anyone had this problem please.
The lines are quite dear but maybe they can be bought separately, as in they would be drivers on their own.

the plastic connectors are sometimes available on ebay.

There are many types, so getting one that fits is tricky! But you may have better luck with seals that fit.
Maybe by a connector for its seal, if not available separately.

Ok , have exposed the fuel return lines again on V8 and turns out to be the same connector that blew adrift the last time.
Have a suspicion that the little d come r clip may have stretched and its not grasping the little flange that the clip keeps it from letting loose. So squeezed the clip a little and gave it another trial.Ran the engine to see if it will hold, before putting everything together.Fingers crossed.