[C. Ludwig]

That's an S5 primary rail. The PD is integral to the rail. This PD is not subject to the same failure (leaking) as the removable S4 PD and cannot be replaced with a banjo bolt. Clean it up and put it back together just as it is.

Install new o-ring on your injectors, just as you've said you're going to. Lube the o-rings before you try to insert the injectors in the rail It's very easy to nick the o-ring and ruin it when you try to insert the injectors into the rail without lube. I like to use assembly lube, motor oil works fine though. Just don't install them dry.

If this is a turbo car you can hook both rails and all the fuel lines up to the engine/manifold before installing the upper intake and pressure test the system that way. I would do that before trying to pressure test the system off the engine. If you do try to pressure test the system off the engine, use safety wire to hold the injectors tight in the rails. You need something very strong to hold the injectors. Tape will not work. You can use properly installed safety wire though to hold the injectors to the rails and jump the test terminal to run the pump just as you described. Doing this on the engine is a safer option though.