For the C5 there are almost no HD pumps available ! Only Opel Zafira 2,2 Ltr. – the pumps are almost identical (except for the drive) The drive head can be used without any problems from the Citroen ! Repair: Opel pump (car or “small displays” get – disassembly – control membranes (replace if necessary -repair kit A M a Zon) – remove the steel ball from the filling nozzle ! Cut thread M12 with 3 steps thread drill – remove all metal chips carefully o riginal Citroen Attach drive part – easy to turn – fastening screws tighten – Madenschrauber M12 x(short) get – fill up operating oil (ATF-4) – by constant rotation of the pump drive – turn until all air bubbles have come out (ATF constantly refill until filling nozzle is half full ! Teflon sealing tape 0.075 on the Madenschrauber – turn in magnifying screw to flush ! mount pump – error code – delete – start engine – idle (800 RPM) pump pressure c a. 80 bar – increase some speed (approx. 2000 RPM) – pressure approx. 100 bar . Engine runs smoothly – everything again paletti – good luck – Bernd