John Deere 4320 Injection pump Diagnosis|Replacement

1972 John Deere 4320 with a week injection pump.
Taking steps through diagnosing the issue then installing a rebuilt pump on the engine.

[@justingutierrez6857]

Is there an o ring or anything on the fuel line connection between banjo line and injector line?

[@joe_preston]

There will be copper washers or bonded rubber washers with a steel ring both could be reused if needed but are readily available.