Removed the 2 pump connectors when doing an oil change just now and it held vac so I'm assuming there is a check valve in the connector to the servo. Any other leak points? Pump works fine as servo starts immediately on engine turnover start and no loss of servo after parked for a few hours. 2012 TDV8 Vogue (L322)

Not specific to L322's, I have seen leaks around the master cylinder 'O' ring and the pedal actuator rod seal, I usually smoke test them. If the non-return valve is passing, then a vacuum gauge on the end of the pipe will show that reasonably quickly

Gave the connector to the servo a 'wiggle' the other day and since then it's not lost vac overnight. I should pull it out and put some silicone grease on it to effect a better seal but don't want to risk snapping another old bit of plastic so will leave it alone unless it happens again. 2012 TDV8 Vogue (L322)