Cat 3126 oil filter change

Can't speak for a CAT but any engine I've ever owned that has a near-vertical filter I will pre-fill it.

azdryheat wrote:
Can't speak for a CAT but any engine I've ever owned that has a near-vertical filter I will pre-fill it.

Yep.

Caterpillar's recommendation is install dry. Their reasoning is that the oil on the bearings will lube for well more than the few seconds it takes to fill the oil filter. And any oil you pour into the filter will do directly to the bearings without ever being filtered.

Now, if this really goes against your grain, take a few more minutes and fill the small outer holes of the filter (the inlets), not the center large hole (outlet).

Brett has the right answer of course. I always do mine dry with no known issues.

lj2654 wrote:
Brett has the right answer of course. I always do mine dry with no known issues.

X2

The filter itself has printed on it to fill the outer holes, provided you bought a Cat filter.

Never thought of that .. fresh Oil from the container is contaminated ?not filtered good enough? after all we aren't talking fuel filter and fine clearance injectors. Just oil and rings/bearings ... But I learned something I guess.

Having changed hundreds of large oil filters I fill them using the large center hole. New oil from a clean container does not need to be filtered. That said I do fill fuel filters using the outside holes as that can be done quickly unlike oil.

I agree they can be put on dry but old habits are hard to break.

At one of the tech sessions at a Diesel RV Club Rally, we started a discussion on this. A guy in back stood up and introduced himself-- retired chemical engineer from one of the top 3 petroleum companies in the U.S.

He said, "Do NOT bet your engine's life that there are never any contaminants in new/packaged oil". As long as it goes through the filter medium before going to the engine, you are fine. Fill the outlet to a filter and that is 100% UNFILTERED oil and not recommended."

But, each of us must decide our comfort level with how to do it.

You can screw a pipe nipple into the hole to prevent oil from going in. Dont tighten it tho, its tapered.