Fuel Injection Pumps

I have a 12A 955 and a 70D 12 Motor Grader. It discusses the need to replace fuel injection pumps when exhaust is no longer clean or when a loss of power is noticed. Mine have clean exhaust and I have no idea if they have experienced power loss, as I have only owned them for a small part of their lives. Can anyone advise on this?

I don,t think the smoke problem shows up with worn pumps too much but bad nozzles in the head will or a dirty air cleaner.Worn pumps you probably will see lower power and harder starting usually along with lifter setting under the pumps not up to specs.Also if cylinders get glazed from idling the engine too much will smoke from oil burning due to this problem.Hard work under load at a steady pace will usually correct this & an oil sobbering from the exhaust pipe is the indication of this sobber problem.If rings are worn bad & the liners you will probably get some slobbering too and the smoke from the oil burning.