Prefilling Oil Filter Instructions

The Cummins manual states:

Fill the oil filter with clean lubricating oil. The lack of lubrication during the delay until the filter is pumped full of oil is harmful to the engine

IF you do pre-fill the oil filter, there is a right and wrong way to do it.

The small outer holes are the INLETS, the large center hole the OUTLET.

Pour all the oil in the small holes. Any oil that gets in the (much easier to hit) large center hole will go to your engine UNFILTERED. Do not assume there are no particulates in new oil (ask any Petroleum Products Engineer).

Many go to a hardware store and find a short pipe that threads into the center hole while pre-filling to keep oil from the OUTLET hole.

BTW, Caterpillar recommends AGAINST pre-filling filters for just this reason – fear of particulates in oil passing directly into bearing areas.

The following values are for oil taken from a newly opened container and submitted to an analysis lab.

Prior to 1999, ISO Codes were expressed as two numbers, such as “14/11” (as seen in the below chart), these represent the ISO code for found particles greater than 5 microns and greater than 15 microns (see code chart below). This chart also includes larger particle counts, those for >75 microns >50 microns >25 microns as actual counts (not as an ISO code)

(1) Contained metal flakes “not uncommon in new oil”
(2) Contained 8 particles/ml over 100um (0.004“). Caterpillar have an ISO 16/13 spec for new fill (and that most bottled oils don't make it).
(3) Dust/debris seen in microscope, recommend filter before use.
(4) 2 particles per ml greater than 100um (0.004”)
(5) One would assume that being Cat, it was pretty well filtered to suit their case.
(6) Noted small particles that appeared to be organic, possibly additives
(7) Noted that this oil has an additive that shows false Antifreeze.