oil filters and by-pass valve question

[jdoe71]

I thought it was a differential pressure across the input and output of the filter. Got that info from this page:

Diagnosing Engine Oil Filters with Collapsed Center Tubes

So the risk I see with a higher PSI bypass is that if the pump relief is allowing 60 or 80 lbs and there's a restriction in the filter you could end up with over 100 lbs in the filter before the bypass opens thus making failure more likely. So I'm guessing that 8 psi bypass pressure is safer since a catastrophic oil filter failure is way worse than bypassing unfiltered oil into the engine.

Agree with Ex-Calif's comment, sure would be nice to know when this condition occurs.

[SkiprJohn]

Aloha Alan,
Sorry if I didn't catch that before. That's a really great explanation. Now I have to do a bit of research to make certain I have the proper filter. Would have a bit of a mess on my hands if the filter blew.
Thanks again.
JohnL

[Alan Wheeler]

Good point Dan. The pressure relief in the pump is the norm in modern engines. I had in my mind we were talking old and small. Although I am not familiar with the engine in question, I just assumed. Assumptions=the mother of all stuff ups.

[never monday]

There are two bypass valves in this system. One in the oil pump. When upstream resistance gets greater than the relief valve. It'll dump the oil back into the pan. Now, the bypass in the filter allows the oil to flow thru without filtration. THis will open at a low pressure.

Now, all this work and you could have just gone to Kubota and gotten a 15853-32430

[jdoe71]

Thanks for the info Pat.
Yes, I could have done that but I would have learned nothing(and came home empty handed). I've learned a lot from the replies on this forum and the research this led me to do.

I learned that Kubota has superseded the oil filter for this engine 2 times, the first was 70000-15241, the 2nd was 70000-74034. The 15853-32430 is for a different series of tractors but will fit this engine. Each is a different physical size, the last one is tiny compared to the first two and the OEM (2.65 dia X 2.51 height vs 3.12 dia X 3.3 height). There's no way I would put it on my engine, it just has to have less filter material than the OEM I am using now and it's only 3 or 4 bucks cheaper. I have a Kubota L4300 tractor and Kubota did the same thing with oil filters for it, the current one is 1/3 smaller than the original. Kubota parts are not cheap up here, I'd pay the extra 3 bucks for the OEM filter rather than use the Kubota tiny one.

I also learned there is a tremendous difference in quality of filters, and with outsourcing by engine manufacturers an OEM product this year may be different next year, with resultant quality questions. Some filter companies make their own filters and the quality is always good. I also learned that bypass filtering is really the way to go with a diesel but it's way overkill with my situation. I learned a lot more about diesel oil, lube systems and filtering than I knew before, so it's a good thing.

I'm not trying to slag OEMs, I just want the best filter possible for a reasonable cost, if that's the OEM then I will stick with it. But I am pretty sure there are filters as good or better than OEMs with consistent quality year after year at a reasonable cost. Thanks again for the input from you and everyone else, it's appreciated.

JD

[never monday]

No problem,

Just a thought...and this is my unsolicited opinion.

Does it really mater if filter a cleans 10% better than filter b if; a) your changing them ahead of schedule. b) the engine is still going to last 8k hrs with either. c) we're all gonna be dead before these iron beasts rot away.

[jdoe71]

Very good points!
As for a) I'm going to go with Universal schedule, I'm more comfy now that black oil is normal

b) and c) if this engine keeps accumulating hours as it has (POs put an average of 26 hours a year on it) it will take another 288 years to reach 8K hours. Puts it into an entirely new perspective! What's that they say about don't sweat the small stuff?
Point taken.