Currently chasing a ‘loss of servo assistance’ when cadence braking, Does any one know what vacuum a vacuum pump on a 200tdi (and similar) engine should make at idle?

Mine makes -26InHG and I don’t know if that’s okay or not.

It also drops by about 10 for one press of the brake. It’s a that normal (pressure drop wise - I know it should drop but not by how much)

NRV tested and leaks so new on the way but would appreciate openions on the vac pump readings!