Jst been through 2 turbo return hoses in as many weeks! What i found was a couple of studs had fallen out of the exhaust housing on the turbo (could not hear the exhaust blowing/leaking). With the studs missing exhaust gas was seeping between the housings directly onto the turbo return hose!

What i have done now is used some 16mm internal diameter oil resistant samco. The only proble is if you try to bend the hose it kinks so i got some copper tube, bent it to 90 degrees and put it inside the samco to stop it kinking.

Replaced the turbo studs and all is well