Euro II D-max has 2 fuel filters? Which is the best fuel filter?

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leoblack9
Posts: 10
Joined: Mon May 17, 2021 1:15 pm

Euro II D-max has 2 fuel filters? Which is the best fuel filter?

Post by leoblack9 »

Hey there, so my 2017 model D-max is Euro 2 rated, so it has 2 fuel filters (one in engine bay and the other under the chassis on the driver side). Engine side fuel filter has a yellow lip and the chassis side is blue. I asked an Isuzu mechanic why is that and he answered that the blue filter catches larger particles compared to the yellow one (finer filtration).

Since diesel in the Philippines is now strictly Euro IV I wonder if I can put any fuel filter for the chassis side since I cannot find any aftermarket part for the blue fuel filter, and the original genuine part is very expensive.

I plan to buy Baldwin/Donaldson fuel filters meant for this truck and change it around 20,000km or 2 years compared to the 45,000km/4yr recommendation by the manual. I use Euro V diesel (58 cetane rating) in my truck from a a local company (Unioil) and fully committed to stick to only one station. Any thoughts?
mydmax
Posts: 1807
Joined: Sat Oct 12, 2013 8:36 pm

Re: Euro II D-max has 2 fuel filters? Which is the best fuel filter?

Post by mydmax »

Leo
Two fuel filters is a good idea. Yours has two OE filters, but in Australia if you fit a second filter as a Pre Filter Isuzu won't endorse such actions, somehow. Figure that one out if you can.
I fitted a Donaldson Pre filter which is 11 microns so as to do the same as what your mechanic mentioned. I believe from Donaldson that my OE filter and Donaldson confirm it as 5 micron.
If you have the pre filter part number and any info of size, thread dia and water trap features etc. Donaldson would be able to supply for you I am fairly sure. Send them any relevant info to the contact on their site.

PS You probably can fit any filter, but one which pre filters AND dewaters and if possible has a sump to catch any water globules is best to have. All to save the main OE filter.
leoblack9
Posts: 10
Joined: Mon May 17, 2021 1:15 pm

Re: Euro II D-max has 2 fuel filters? Which is the best fuel filter?

Post by leoblack9 »

Thanks for the chip in, mydmax. As far as I know, the OE filter in the engine side is rated 10 microns according to Donaldson's OE equivalent filter (https://shop.donaldson.com/store/en-ph/ ... stid=29185), I don't know what rating is the blue pre-filter as I still haven't found any equivalent for it, maybe 30 microns?

The mechanic I've asked told me that I could put two 10 micron filters but the fuel flow will be impeded, the blue and yellow fuel filters work in unison in providing good flow. I'm not sure if the blue filter has any dewatering function in it, since the housing doesn't have a water drain valve.
mydmax
Posts: 1807
Joined: Sat Oct 12, 2013 8:36 pm

Re: Euro II D-max has 2 fuel filters? Which is the best fuel filter?

Post by mydmax »

I doubt very much the OE main filter is 10 microns, pretty useless if it is. 5 or smaller usually for Isuzu, Anything larger will allow particle scuffing and destruction of the High Pressure pump element, some makes use 2 micron. A 30 micron pre filter will strain the blowflies and mozzies out of the fuel but pass stuff big enough to load the main filter. Quite useless really, if serious about filtering. Even some diesel specialists want to use that size to filter for a CRD and they don't seem to be able to get away from the idea. or they have old stock they want to sell. Crazy. Around 10 is far better for pre.. A 30 micron is what mechanics are used to with conventional diesels, CRD require far finer filtering. It is the physical area of the filter medium which determines any restriction, not micron size alone. The fuel "pass rate" is what you want to know, so as to select the correct size. You will need filters which pass more than 120 L/H. Remember, as a filter catches, it becomes restrictive anyway and more effective but less flow rate.

If you can find a filter to fit as your PRE, which has a bowl and dewaters the absorbed water held within the fuel, will be far better
leoblack9
Posts: 10
Joined: Mon May 17, 2021 1:15 pm

Re: Euro II D-max has 2 fuel filters? Which is the best fuel filter?

Post by leoblack9 »

For a prefilter the P505973 (https://shop.donaldson.com/store/en-ph/ ... stid=29185) that is 10 microns paired to this primary filter P506093 (https://shop.donaldson.com/store/en-ph/ ... prod340529) which is 5 microns should be good?

I'm afraid I can't go the aftermarket route yet since there are no big outfits here that provide aftermarket diesel prefilter products. So for now I have to make do with the stock housing.
mydmax
Posts: 1807
Joined: Sat Oct 12, 2013 8:36 pm

Re: Euro II D-max has 2 fuel filters? Which is the best fuel filter?

Post by mydmax »

Leo
If you can get those filters from Donaldson then all is complete and they are aftermarket from Donaldson. You could contact Donaldson and see if if they would send a Pre filter Kit to you, as an alternative to the OE pre filter. Donaldson are not going to recommend a filter which will restrict fuel flow, they have been in business too long to do that. Your mechanic may need to improve his understanding and knowledge of modern fuel systems though. Be careful if acting on his recommendations. Follow what Donaldson indicates is a solution.
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