Fuel injection pump condition evaluation for overhaul

The Engine Maker's manual states the overhaul RH limit and/or period for fuel injection pumps overhaul. It is highly advised to stick to Maker recommended intervals. However, the overhaul could be done earlier or later depending on many factors like pump condition, Owner requirements, Engine usage schedule, repair convenience etc.
To consider fuel injection pump overhaul its condition must be evaluated as per below:
- Check for leakage from pump top cover
- Check for internal leakage: from the pump FO drain, signs of leakage detected at tappet roller in the camshaft space
- Compare current fuel pump index at certain load to the corresponding trial records/testbed measurements for same load and RPM.

If leakages observed or fuel pump index increased 10 or more the pump certainly must be overhauled with a replacement of worn parts.