Davco water separator filter, which one for the D12

Davco says to use a 25 micron one ( fleetguard fs19765 ) but recently a volvo dealership told me to go to a 50 micron one ( fleetguard fs19729 ). Can someone with real knowledge tell me which one I should use. Thanks.

 

Got that and know that but as I said, volvo told me to use the 50 micron not the 25 micron.

 

Actually I have three filters. The davco, then the volvo water separator filter ( which I am told is 25 microns) then the volvo long life filter which I am told is a 7 micron filter. But davco state to use the 19765 filter in there unit, which is 25m.

 

No, the filter flow is as follows.

1st. The davco, currently with a 50 micron filter as per advice from volvo dealership. Davco however call for a 25 micron filter, as per the chart you posted a link to.

2nd. Volvo water separator filter. Told by dealership that that is a 25 micron filter.

3rd and final, 7 micron long life volvo fuel filter.

i got the logic, but should I have a 50 micron or a 25micron as the 1st filter?

 

Well not really. IMO you can never over filtrate. The cleaner fuel getting into the cylinder the better. Hence the FASS fuel polishing system. The water separator as a term is a bit misleading. It's just a larger micron rated filter, as water particles are larger, but obviously it will stop other particles. Having a progressively smaller micron filtration series of filters works by protecting the next filter in the series from clogging. 50 protects the 25 and the 25 protects the 7. Thus extending each filters service life. I was running 25,25 then 7. The Davco is much easier to change and has a higher capacity than the Volvo 25. I have run that configuration for a year with no problems. Volvo in New Haven IN told me to go 50, 25 then 7. Perhaps I'm the only one with this setup. So I will just watch my mpg, performance and time before the filters get clogged and determine which setup is best.