how to check fuel return hose on 2.5 DI for leaks ?

[peteMK2C]

Hi everybody,

The fuel supply line is now completely free of any air / bubbles but I keep on having trouble with my diesel pump. The engine still misfires with blue smoke and does not reach max. RPM. That said it may also be a leak / air from the fuel return line that goes into a valve on the Lucas.

So I was wondering, what might be the best way to check the fuel return line that goes into the Diesel Pump for leaks.
I was thinking of replacing the plastic hose with a suitable clear hose but therefore I have to remove the plastic hose, which will rather destroy the hose, given how tight it is on the connectors.

Greets,
Pete