How to repair the fuel pump on Vectra C Z22YH engine
After removing the fuel pump
If the seal was un seated then the fix is simple.
Reseat the seal.
remove the 3 torx screws that hold the 2 halves of the pump together.
then separate the 2 halves, watch out for the hydraulic oil that is inside.
remove the pistons and cylinder block.
drill hole in line with hole in the pressure equalizer, then tap it to accept new bolt.
cut bolt so it only goes into housing level with the inside.
Reassemble pump , refit the to sides together.
Fill with hydraulic fluid through the new hole (using syringe). turn the hex drive nut to ensure the fluid reaches all parts.
Now the important bit.
with the new filler hole at the top push the rubber pressure regulator with the blunt end of a drill bit.
some of the fluid will be released, keeping the drill but pushed in clean the excess fluid from the filling hole
seal the filling hole with the bolt and some thread lock (nail varnish)
This fixed my pump and it's now back on the car.