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Discussion Starter #1
Somebody had to get this going.


Duramax owners be aware there is a controversy going on about the ability of the stock fuel filter to adequately filter fuel to a level that protects the injection system.

Fuel analysis were done and this was confirmed.

Many Dmax owners have taken it upon themselves to design a solution that improves filtration by adding a secondary filter.

In the process, we have found that since our trucks use a vacuum draw system, adding more restriction through the use of super efficient fuel filters is creating some outgassing and air issues on some of the designs.

Some guys are using a lift pump to eliminate the vacuum with great success.

Others have not found air to be an issue..... at least from an operational perspective. Air still could be a factor in the long term.
 

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I was wondering when someone was gonna bring this one up!! I am still on the fence about what filter to get, pre or post, etc. A lot of the talk has been way over my head on analysis and stuff like that. Just goes to show that you are never done learning!! Lots of good info out there, maybe I can start to make some sense of it!!


Good to see you over here Hoot!


Bob
 

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hoot--Thanks for starting this post. I am like 4X4man, been sitting on the fence on this one, I know I need extra filtration, but just haven't deceided pre or post. I did talk to my dealer's service manager about the warranty issue and he said no problem with the warranty if I added extra filter. I ask him pre or post and he said he would do a pre filter, Quote--Not much room for post--Unquote. Told him about people putting them under the air filter box and he was not to impressed with that idea. Didn't say way. Do we know if the air issue is present with the pre filter without the lift pump? Do we know if the lift pump is hurting the injections pump on out motors? I just don't want to cause more problems than we already have. Only have 29,000 on the truck now and have not had one problem with it yet. Sorry for the long post, but I just have to be sure I am doing the right thing the first time around and don't cause problems that I don't have now.
 

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I have been debating on doing something similar. I don't like the idea of cutting into the stock fuel system because of warranty issues. So, has any done this and had warranty problems?

I was instead thinking of adding a secondary fuel tank, somewhere between 25-50 gallons. I would never add fuel (from filling station) to the stock tank, but instead fill the secondary tank. I would use two good fuel filters and a lift pump to fill the stock tank from the secondary tank (i.e. clean fuel). This would keep the stock fuel system stock, give me clean fuel, plus extra capacity.

What do you guys think?
 

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Discussion Starter #5
cdhd2001 said:
I have been debating on doing something similar. I don't like the idea of cutting into the stock fuel system because of warranty issues. So, has any done this and had warranty problems?

I was instead thinking of adding a secondary fuel tank, somewhere between 25-50 gallons. I would never add fuel (from filling station) to the stock tank, but instead fill the secondary tank. I would use two good fuel filters and a lift pump to fill the stock tank from the secondary tank (i.e. clean fuel). This would keep the stock fuel system stock, give me clean fuel, plus extra capacity.

What do you guys think?
I beleive George Morrison does something similar but he filters the fuel "off" the truck. I believe he has a big holding tank with major filtration.

I think what you are doing is a good idea as long as it doesn't become a real hassle keeping the truck tank filled. The extra tank is a big benefit but at the same time is extra space and weight.Edited by: hoot
 

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Hoot,

I could probably put in a fuel gauge for the second tank and a switch in the cab for the transfer pump. Shouldn't be too much hassle. Most of us that tow would love the extra fuel capacity. The stock 26 gallon tank is not much!
 

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Discussion Starter #7
cdhd2001 said:
Hoot,

I could probably put in a fuel gauge for the second tank and a switch in the cab for the transfer pump. Shouldn't be too much hassle. Most of us that tow would love the extra fuel capacity. The stock 26 gallon tank is not much!
You could triple filter using that method!

They sell systems for marine use that actually run for 12 hr intervals, circulating the tank fuel through the filter.....

Looky HereEdited by: hoot
 

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Hoot-


If I remember correctly, you are using a Racor Post OEM with no air problems, right?? I really don't want to add a lift pump to the truck to get rid of the air. But I guess I wouldn't know I had air until I installed the second filter. I just wonder how one person in particular is able to run three filters and not have a lift pump, but others can't even run 1 extra filter without problems.


The saga continues...


Bob
 

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Discussion Starter #9
4x4man said:
Hoot-


If I remember correctly, you are using a Racor Post OEM with no air problems, right?? I really don't want to add a lift pump to the truck to get rid of the air. But I guess I wouldn't know I had air until I installed the second filter. I just wonder how one person in particular is able to run three filters and not have a lift pump, but others can't even run 1 extra filter without problems.


The saga continues...


Bob
The Racors seem to have a head design that doesn't accumulate air. You also have to figure at least a few of the installs might not have been done airtight so you can't blame all of it on the filters. The more plumbing you do, the more places air can get in.... KISS principle.

A well assembled system will not leak though no matter how many junctions there are.
 

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Thanks for the info Hoot!


Looks like DIS is still out of these Racor setup's according to their website. May have to give them a call and find out what's up. The weather is still good out here, and if I am going to do this, it would be nice to do it while it is still warm!! I guess I'll have to do some searching to see who else has these setups in stock.


One other question. Are the 250psi Parker Fuel lines necessary?? Not that I am being cheap, but what is the difference between say regular fuel line and the Parker Fuel line??
 

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Discussion Starter #11
4x4man said:
Thanks for the info Hoot!


Looks like DIS is still out of these Racor setup's according to their website. May have to give them a call and find out what's up. The weather is still good out here, and if I am going to do this, it would be nice to do it while it is still warm!! I guess I'll have to do some searching to see who else has these setups in stock.


One other question. Are the 250psi Parker Fuel lines necessary?? Not that I am being cheap, but what is the difference between say regular fuel line and the Parker Fuel line??
Since it's a vacuumm system, you're better off with a higher quality line that avoids collapse and holds up to abrasion. A small price to pay if something goes wrong.
 

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Hoot-


Thanks for the input. I just wanted to make sure that this wasn't something that was way over kill.....not that I am one to over buy on things or anything..



I have seen a few instances where paying more didn't get you more but a lighter wallet. It is nice to know this isn't the case with this fuel line. Again thanks for taking the time to answer my elementary questions on this. The threads on the other board were just too far along for me to be asking these questions or starting a new thread.
 

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I'm reposting this message to incorporate significant changes due to new, expert, explanations on cavitation.


There are two ways that you can mount an additional filter: Either before, upstream of the factory filter (pre-oem) or after, and downsteam of the fatoiry filter (post-oem).


Fuel filter fuel analysis results posted on TDP indicate the best filtration thus far have been achieved with a pre-OEM filter and the OEM filter.


Many have found that mounting their 2 micton Baldwin and CAT filters post-oem have caused air to be trapped in the filters causing random stalling and "no starts." Inexplicably, the filters that cause stalling in some trucks, work just fine on others. Those mounting their filters pre-oem have not reported any stalling/no start problems whatsoever. The RACOR filter is the only filter I know of that can be mounted post-oem w/o any reports of causing stalling.


Those that have installed post-oem filters found that they could cure the stalling/no start problems by installing a lift pump that prevents the entrained air and vapor found in the fuel from normal outgassing that occurs in our stock fuel systems. Air testing performed by chuntag95 indicate that even stock systems produce outgassing and air in our fuel systems - it's normal.


Some will try to selll you a lift pump to eliminate this air claiming that it could cause cavitation. Experts contradict this stating entrained air and outgassed air bubbles do not cause cavitation - airless cavities or voids in the fuel caused by vacuum, and not entrained air or air bubbles, cause cavitation.


For example, when there is suction but not enough fuel to feed a pump, a cavity or void occurs. When pressure is reapplied, this cavity violently collapses which can etch and damage metal.


Moreover, in fact, there has not been a single report of any cavitation problems in the stock Duramax or in Bosch common rail injection fuel systems that I have seen.


To the contrary, evidence points to the opposite conclusion that the Bosch commoin rail fuel sytem is highly reliable. Reports indicate that with properly filtered fuel, our fuel systems should perform reliably, well past the expected service life of the truck. For example:


BROKERS, a long haul car broker, has claimed 2 of his Duramax trucks have gone over 400,000 milies (800,000 combined) with only one injector failure between them.


BROKERS stated that he uses two filters: One filter in the bed with his auxuliary tank and one frame rail mounted RACOR 2 micron filter. He transfers his fuel from the bed tank to the OEM tank, BUT DOES NOT HAVE A LIFT PUMP.


To-date, no one has reported any Bosch common rail injection system fauilures due to cavitation in any forum or reference that I have been able to find. If the design were poor, and if air caused cavititaion as some claim, the entrained air normally found in diesel would cause cavitation on a moleular level.


Apparently, Bosch knows their diesel injection stuff. GM dumped their long standing injector suppliers for the Bosch common rail system and in 2003, so did Dodge. Our common rail system is also used in Mercedes, Alfas, Volvos and VW's.


Bosch has been making diesel injection systems since 1922. Bosch began marketing their common rail injection system in 1997. There are 3,500,000 Bosch common rail systems in vehicles in the U.S. and over 10,000,000 world-wide since 1997. Therefore, with so many common rail systems in real life use, if there was a cavitation problem, I feel it would have been reported and a matter of common knowledge.


There are vendors who have sold many post-oem filter kits only to learn that their filters trapped air that caused random stalling. I had ordered one and this vendor did not warn me about the air/stall problems when I placed my
 

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Discussion Starter #14
Thanks HB
 

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While I'm on the subject of filtration... George Morrison (AVLube.com where most send their oil and fuel samples for testing) provided fuel cleanliness standards to shoot for.


The three main filters folks are usining, the CAT, RACOR and the MEGA filter all have proven by testing to filter their fuel well within the cleanliness standards.


I prefer the CAT 1R 0749 that comes with the Nictane pre-oem Bracket because they are huge buckets that will probably last as long as the OEM filter would have, 15,000 miles, and they are readily available everywhere. It was the CAT high efficiency filters that set the standard.


BTW George quoted CAT filter testing results that proved that back pulsations/vibrations from the pumps and injectors lower the effectiveness of filters. Post-OEM filters mounted in the engine cmpartment are in direct line for these pulsations and engine vibrations.


In the pre-oem configuration, the OEM filter acts as a damper for these back pulsations. Also mounting the pre-oem in the Nictane position or on the frame rail eliminates direct engine vibration.


George's recommendations in relation to filtration, plus, CAT filter information can be found in the TDP link below:


http://forum.thedieselpage.com/ubb/ultimatebb.php?ubb=get_topic;f=3;t=006528#000000


George's Main Filtration Thread, described as "The Mother of al Filtration Threads," is at TDP link below:


http://forum.thedieselpage.com/cgi-bin/ultimatebb.cgi?ubb=get_topic;f=3;t=004373
 

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Just what I was thinking Hoot. Out gassing is not a hydraulic term and has no meaning when discussing our fuel system. The previous post has more inaccuracies in it than my filter has holes. Later! Frank
 

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Frank Blum said:
Just what I was thinking Hoot. Out gassing is not a hydraulic term and has no meaning when discussing our fuel system. The previous post has more inaccuracies in it than my filter has holes. Later! Frank

Please clarify, what inaccuracies?


Are you saying that the pre-oem filtration did not provide the best fuel filtration test results?


Are you saying that our stock fuel systems do not outgas/produce fuel vapor under vacuum and heat?


Not according to chuntag95 who eliminated possible air leaks by running a clear line directly from the tank to test for this and still found air bubbles going into the pump.


Have you seen a single report of cavitation problems in the Bosch common rail injection systems?


Are you saying that George Morrison has not quoted CAT research saying that back pulsations vibes from the pumps, injectors and engine adversely affected filter performance?


Please clarify. What inaccuracies are you talking about?
 

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Discussion Starter #18
The part I take loosely is about the pulsing from the injectors. Remember the tests were done on a totally different engine. The injection system on the CAT's are HUEI not HPCR.

"The volume of each Duramax common rail is 16 cubic centimeters and they serve as reservoirs to provide a constant volume of fuel and dampen oscillations as the injectors operate."

Either Caterpillar did not know about the pulse/vibration induced problem or they didn't concern themselves with it. They were told about it when the study George Morrison mention was completed. From the same line of engineering came the CAT designed injection system used by Navistar on the 7.3 PSD. They ended up finding out the pulsations may be a factor in the cackle issue. This is a drivability issue not even getting into filtration.

In summary, it's not wise to compare the results of a test on CAT engines to what "may or may not" be occuring on the Duramax/Bosch injection system until the two system properties are well known.

I would agree that mounting a filter solidly to a running diesel engine block does not add to a filters efficiency, any engine that is.Edited by: hoot
 

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Just passing along George's opinion of a possibility of why the OEM RACOR, supposedley rated for 2 mic, wasn't performing up to spec. He thought the poor OEM filter performance may be related to pulse feedback or engine vibes.


George stated that CAT actually redesigned their filters to compensate. The redesigned filters are the CAT High Efficiency filters that come with Nick's Nicktane Bracket kit.


Your next post-oen RACOR fuel test, combined with other post and pre-oem RACOR terting, should be a good indicator of whether there is a problem.


If there is a trend showing the post-oem RACORS' results to be regulalry inferior to pre-oem RACOR then that may be a good indicator that pulses or vibes are adversely affecting post-oem filter performance.


I believe, so far, the post-oem RACOR fuel test results have been too skewed by bad sampling to be used for comparison.
 

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Mr X,


Despite your self proclaimed extensive knowledge of fuel injection and filtering systems you fail to grasp a few simple and basic concepts here. Any of the filters you mentioned can be installed as a primary or secondary filter - all you have to do is switch around the fuel lines and possibly reposition the mount. Why don't you know this?


What's up with basing a major part of your argument on a ghost? Coming from someone that demands strong hard evidence this is strange behavior indeed. Give em the old razzle dazzle with 800,000 mile claims. You could give your argument a overdose of the big blue pill viagra and your arguments are still limp and lame.


The fuel reports that have been done indicate that all of the filters seem to be doing a much better job than the factory filter, with a few exceptions. You seem more hell bent in dissing someones product and ignoring results that don't support your view rather than providing a knowledgable discussion.


Any pics of the new and improved Nicktane.com bracket?
 
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