Focus 2002 TDCI - Fuel supply manifold - Dieselian

Does anyone know why you have to change the fuel injector pipes when changing the fuel supply manifold?

Focus 2002 TDCI - Fuel supply manifold - Peter.N.

I think its a safety precaution as leaks on the high pressure side can be dangerous, I don't think everyone does it though.

Focus 2002 TDCI - Fuel supply manifold - Dieselian

Thanks i have changed the fuel manifold sensor but the car is now off two cylinders.