Thread: Replacement interval for Donaldson filter elements

Originally Posted by rathgar

Hi Tristan,

I had never heard this before do you have any more details or links to studies?

Thanks

Have a read through this thread. Air Filter Tests (Finally)

Actually, everyone needs to read what Ben/isuzurover says regarding air filtration in this thread.

Originally Posted by rick130

Have a read through this thread. Air Filter Tests (Finally)

Actually, everyone needs to read what Ben/isuzurover says regarding air filtration in this thread.

Thanks.

I had a skim through the 8 pages and there is lot of good information re filters (i think I have read it before).

The data in the graphs shows clearly that the K & N filters work better (at filtering dust) when partly clogged. But given that it also shows they aren't up to the job of actually filtering anyway, why bother using one. I haven't, and would never, use them where removing dust from the air was what you were after from an air filter.

The data (that I saw) doesn't show back to back tests of the same brand and model of other types (brands) of filters with regards to an improvement in filtering efficiency as they become clogged. It may be true but not shown in that data.

If it is true that as an air filter becomes clogged it is able to remove finer particles. This has to compared to the loss of airflow to the engine as it becomes clogged which I think the data shows (but there also seems to variables in the model of filters being compared).

Read what Ben says, he explains how an air filter works and how as it loads it increases efficiency (and I think it's somewhere in there how a fuel filter works differently !)

He's a filtration engineer, he designs and lectures on filtration systems and has worked on research for the big three, Mann-Hummel, Donaldson and Cummins/Fleetguard.

Of course it's always a trade-off between flow and efficiency, which is why pressure differential indicators were invented !

Yes I read what he said I am just pointing out that there is a lot of comment in that discussion based a a couple of graphs that don't document the whole equation.
If you stop and think about the extreme, a 100% blocked filter, then off course there wont be dust particles getting through but that's because there is know airflow to carry them.

Regularly clean and or replace your filters - don't operate them at a base level of being 80% clogged. That is crazy.

Originally Posted by rathgar

Regularly clean and or replace your filters - don't operate them at a base level of being 80% clogged. That is crazy.

The point is that people clean or replace far too frequently, and cleaning has the downside of potentially damaging the media.

I can't be bothered looking, there's data somewhere, and IIRC that Donaldson element I supplied for that test had at least 20,000km of use on it already.
At the time I lived well out in the bush and travelled majority dirt roads everyday. The filter still had plenty of life in it, it was no where near its service life in terms of pressure drop.

OK, here's the Donaldson (not land rover) part numbers for the air filter elements and service indicator for both 4x4 and 6x6.

4X4
inner.........P90-0434
outer.........P90-0433
Service indicator...RBX00-2252

6X6
inner........P90-0434
outer........P90-0611
Service indicator....RBX00-2251

Originally Posted by Bearman

OK, here's the Donaldson (not land rover) part numbers for the air filter elements and service indicator for both 4x4 and 6x6.

4X4
inner.........P90-0434
outer.........P90-0433
Service indicator...RBX00-2252

inner........P90-0434
outer........P90-0611
Service indicator....RBX00-2251

Assuming the second half of the post is for 6x6...

From those part numbers the 4x4 service indicator is a 25" and the 6x6 (with turbo) a 20". Seems around the wrong way?

How do you find your service indicator with a turbo?