Just a thought(fuel filtering)

[DURA-MAX3]

I was thinking today, i know real dangerous, but anyway, if the stock filter, from what i have been told is 2 micron but only about 50 to 60 percent efficient, then what is the big deal about going pre-oem like alot of us have done. I have the Cat pre filter and it is much more effiecient but i was wondering if it is really that big of a deal...looks like to me that the fuel is going through two 2 micron filters instead of the smaller one first that many have said was wrong...I would like to know you all's thought on this but don't want a war on who is right or wrong...Thanks in advance for your opinion's...

[jbplock]

Dura-Max3,

There are Pros and Cons to the PRE and POST filter installations and both methods have produced results that meet the ISO fuel cleanliness targets -including the PRE-OEM CAT. I also think all the popular 2-micron choices – Baldwin, CAT, RACOR, and Stanadyne are good. With a PRE-OEM filter it may need more frequent changes - not a big deal. The other point to consider is that there have been reports of failures of the OEM filter, which could potentially deliver unfiltered or contaminated fuel to the injectors. So to mitigate this risk just change the OEM along with the CAT at 10ki miles intervals (or less), use a good additive and buy fuel from a good high volume dealer. The 30-micron pre filter (Stanadyne FM100) I have on my setup looked all used up when I changed it at 10kmi. IMHO your decision to add a PRE-OEM CAT filter was a good one and an improvement of the OEM system -it can only help your engine.

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[2fast2]

Just an FYI for those people considering adding additional filtration: There is a group buy getting organized at another internet forum for one of the suitable units jbplock mentions above. Might help save folks some money.

Jim

[Kennedy]

I've had guys install my kit pre or post. The beauty is, that it is just a swap of hoses. My preference remains post. The OE filter should be changed at the bare MINIMUM of 15k, and I personally suggest 7500-10k or whatever coincides with regular maintenance.


The key here is multipass. To do multipass, 2 filters is quite helpful, as the first time through is already a multipass. One to remove the larger stuff, and then a second to get a large percentage of what passes through the first. A large percentage is returned to the tank where it is again picked up and run through the filter(s). I personally have never seen a dual filter setup specifically designed to have the better filter first. It won't hurt, but again, the most efficient way would be to have the better filter second.


The OE Racor has been stated 98% efficient at 4 microns. Now keep in mind, that as I am told, this is a lab conditions test consisting of MULTIPLE passes to continually refine the fuel...

[BadDog]

Some people have mentioned potential warranty excuses with the filters in pre or post (though more in post). Here is a suggestion I haven't seen before (maybe I missed it?). Why not use the quick connects to create a system that could be removed before warranty work like the Edge box? I know the quick connects are sometimes a source of problems on their own, but would this be in line with the "out of sight, out of mind" approach?

[DURA-MAX3]

Kennedy:::
I see that you said that the factory filter is 98% at 4 microns...I thought it was 2 microns, therefor leading me to think that the fuel was just passing through two 2 micron filters, the Cat just being more efficient. Thanks for your reply...

[20050528|8|000731|000000|205.188.117.71]

By running a finer filter first should render the second, more course, filter useless. That is assuming that the finer filter is perfect. One thing is certain, if you run the finer filter first it will catch most of the contaminants and require changing more often. By running a course filter, or pre-filter, you take out the larger particles only and leave the finer particles for the secondary or finer filter. This way you divide the particles between two filters which should result in less often filter changes.

I have changed my mind on what to do in my truck a few times already, and may change again before it actually gets done, but if I were going to do it today I would install the Stanadyne filter / feed pump and the Racor kit for our trucks (these are expected to be delivered in the next week or two) with the protective bracket before the factory filter. I plan to follow the instructions for the Racor kit by taking the hose from the tank into the Stanadyne. Hook the Stanadyne directly into the Racor. Take the out from the Racor into the hard line that previously went onto the hose to the tank. The Racor kit comes with a R60T filter which is rated at 10 micron and 98% efficient. I plan to swap in a R90S filter which is a 2 micron and almost one inch taller than the 60 series filter. The added length should buy extra time between filter changes. There is an even larger, four inches larger than the 60, R120S filter, but I am worried about clearance issues under the truck, and the filter guard bracket won

[BadDog]

Yes, it is down line so they can't say your filters ****d and cause a problem, but they can say that your lift pump created positive pressure where there should have been suction (lower than ambient) from the stock pump and that caused... :rolleyes: If they want to, they can and will use any excuse to lay it on you. That's one of the reasons I haven't done anything with my truck yet. But, they will probably find some way to blame my oversize tires for failed injectors...

[Kennedy]

Originally posted by DURA-MAX3:
Kennedy:::
I see that you said that the factory filter is 98% at 4 microns...I thought it was 2 microns, therefor leading me to think that the fuel was just passing through two 2 micron filters, the Cat just being more efficient. Thanks for your reply... The reality is, all these efficiency ratings mean NOTHING unless compared by a standard. There are SAE standards that pertain to flow rate, fluid viscosity, etc. to establish things like beta ratio when testing the performance of a filter.


A window screen can catch particles as small as 1 micron, therefore one could claim that it filters at 1 micron. :rolleyes:

Caterpillar does not use the SAE standards when testing from what I am told.

The thing that matters is that 2 filters are better than one, and if the first filter relieves a significant part of the load, the second one only makes the fuel that much better. Get the big stuff with the first filter. The OEM unit WILL catch some particles down as low as one micron. Then the secondary comes in and further refines the fuel. A large portion returns to the tank, and so long as little wear is generated in the fuel system, the fuel will get cleaner with each pass...

[a bear]

Yes, it is down line so they can't say your filters ****d and cause a problem, but they can say that your lift pump created positive pressure where there should have been suction (lower than ambient) from the stock pump and that caused... If they want to, they can and will use any excuse to lay it on you. That's one of the reasons I haven't done anything with my truck yet. But, they will probably find some way to blame my oversize tires for failed injectors... I had hammered this warranty thing through my head for a long time.
Choice 1 was to run stock to avoid warranty issues. The down side to this is if you reach the end of the warranty period without problems you now have 100K miles of a higher progressed wear to the pump and injectors due to the higher volume of wear particles that were introduced over the cource of these miles. Now your on your own.
Choice 2 was to install secondary filtration which would greatly minimize wear during the coarse of thewarranty and have a better shot at extending the life of the fuel system for the long haul. I discussed this with my dealer and they agreed. It is JMHO that the larger percentage of dealers would be OK with added filtration. We would all benefit. Especially the ones who have the reputation of having the longest lasting trucks. Approval for most of us may only be a short discussion away.

I guess one of the main points to consider here is how many miles you plan on keeping your truck. :D

[maxinDixon]

I usually keep my trucks for about 100,000 miles and then hand them down the company line as the need arises. I would prefer to either have a good salable unit or a good dependable truck for my help to drive should I keep the truck. Added filtration is a must IMHO and is cheap insurance.

[GT]

I added the mega filter post oem on my truck about 1000 miles before I took my truck to the dealer and had all 8 injectors replaced under warranty at 49,000 miles. I told the service manager about the filter and he ask where it was installed but didn't have any problem with it.This is only one case but if GM was trying to get out of replacing injectors on warranty this would have been a good time to do it.IMO I don't believe GM will try this as they know the filter is the weak point in the fuel system.I also believe the power boxes have contributed to the injector problems. Maybe this should be a new post if others have any thoughs on this please reply but please no flames as I have no interest in a fight and will not reply.

[kerry witherspoon]

Well i have watched the debate on filters and have thoght about using racor p2 2 micronpre oem with j.k mega both in a pre oem . The p2 racor has a 10 psi pump put in a bypass reg set 2 two psi to stock filter rest returned to tank. Cost is higher but with bypass and 2 pre filters fuel will be ultamatly runn through filers many times befor used. Good idea or bad?

[Flyboy]

I have been running a raycor to lift pump to cat for about 6000 miles now. I have no regulation and haven't seen any need for it.

[a bear]

GT Said

I added the mega filter post oem on my truck about 1000 miles before I took my truck to the dealer and had all 8 injectors replaced under warranty at 49,000 miles. I told the service manager about the filter and he ask where it was installed but didn't have any problem with it.This is only one case but if GM was trying to get out of replacing injectors on warranty this would have been a good time to do it.IMO I don't believe GM will try this as they know the filter is the weak point in the fuel system.I also believe the power boxes have contributed to the injector problems. Maybe this should be a new post if others have any thoughs on this please reply but please no flames as I have no interest in a fight and will not reply.
Are you pertaining to pressure or pulse width boxes. IMHO if you are not running a pressure type box you should not cause increased wear to the fuel system during normal driving. Diesel engines only use the amt of fuel(through the injectors) needed for the horsepower requirements of a given job . However you can cause increased wear to the drive train. Your right foot will determine how much. :D

[chuntag95]

JK makes an excellent point. The OEM will catch particles that get through the pre units. I think adding a finer filter, whether it's before or after is a good thing. I did both so I could argue either side. :D Actually, I have a 30 to 4 to 1 micron order. It will be the most efficient in theory, however, the amout is almost impossible to quantify in real life. Since the theory said it should be better, I went with post for my finer (aka Mega). Putting the 30 before the OEM is also helping. The more you filter, the cleaner the fuel, the longer she lives.

[dmaxstu]

Since I last visited I also installed a Cat pre filter but before I did I did some close scrutiny and comparison with other filters. I came to the following conclusion that Cat by far makes a superior filter and anyone using that filter can do no better in fuel cleansing. One only has to see under what conditions Cat filters are used on their equipment to realise they have to do a good job of it. I only wish there was a Cat fuel filter that would fit on the OEM mount.

I have a 135 Gal. fuel tank in the bed which I use on long trips.I just realized that that would contribute to clean fuel. Judging by the size of the fuel lines about half of the fuel going to the engine is returned to the tank so the last 1/4 tank has to be super clean after passing through 2 fuel filters numerous times. Stu

[jbplock]

Stu,
CAT indeed makes an excellent filter and it's a good choice for added filtration on the Duramax. Independent testing by several forum members has also shown that all the popular filter choices from Baldwin (MegaFilter), CAT, and RACOR can meet the ISO fuel cleanliness targets for high pressure diesel injection systems when installed on the Duramax. All current data has been compiled in the following files including a-bears latest results with a CAT filter on the JK Megafilter mount.

Fuel Test Results – PDF (http://home.usadatanet.net/~jbplock/ISO/OC_Dmax.pdf)
Fuel Test Results – Excel (http://home.usadatanet.net/~jbplock/ISO/OC_Dmax.xls)
(The yellow highlighted entries represent the best results to date.)

(See ISO Contamination Code Table (http://www.edm-mechatronics.com/iso_table.htm) for an explanation of the ISO codes)

Also, if anyone has fuel test data they would like added these files please sent it to diesel1 at usadatanet dot net

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