Fuel filters on 2013.5

[Jim W]

Can someone help out an old hydraulic retired engineer.



I have a question, why does Ram have a 4um fuel filter ahead of the Fleetguard 5um/3um fuel filter that is on the engine? I asked this question in the fluid meeting and the presenter did not reply and kinda skipped over the question. I always thought that the larger micron filter in line would be first and then the small size would be after the first filter at least that is how I have my set up on my truck.



Maybe something new that they are doing know?



Jim W.

 

[cerberusiam]

Need to look at absoute ratings. A Fleet guard 5/3 is acutally courser than a 4 um absolute if the 3 is only nominal. That could be 50% nominal, it is hard telling.

Need to know the true ratings of the filters. Either way, filtering thru even 2 of the same rating is better that one.

I thought the initial filter was 7/5 um and the final was 3 or 3/5. Too many unlnowns on what the filters are actually rated for.

 

[gtobey]

Can someone help out an old hydraulic retired engineer.



I have a question, why does Ram have a 4um fuel filter ahead of the Fleetguard 5um/3um fuel filter that is on the engine? I asked this question in the fluid meeting and the presenter did not reply and kinda skipped over the question. I always thought that the larger micron filter in line would be first and then the small size would be after the first filter at least that is how I have my set up on my truck.



Maybe something new that they are doing know?



Jim W.

I was trying to understand the same thing, but they wouldn't address it. I do know that some filters have a very low micron rating, but the percentage of particle filtration in one pass is not 100%. So, then the one on the engine has two elements, a 5 and followed up by a three. By the time it gets through that, the fuel should be filtered down pretty close to the 3-4 micron they are looking for. However, I'm glad they recognized the need for a primary and secondary fuel filter and did something about it.



You are right that most all (good) fuel filtration systems started with a primary filter/separator of either 150 or even down to 30 microns, then the secondary filter(s) went to the final ratings specified by the manufacturer. Now with the common rail systems, 2-5 micron filtration seems to be their ultimate goal.



That separator element may have a "water block" or "hydro" treatment to repel any emulsified water, and that treatment tends to improve the operation of the primary filter, as he said, up to the point where water could breech the element. Probably wouldn't happen unless the water in fuel light was ignored, or didn't work... .

 

[CRath]

I was wondering the same thing about the lack of an answer from the Ram folks at the TDR gtg, then it dawned on me as to why they didn't really provide an answer and why anyone would put that that filter in front of a newly designed 5/3 micron filter. Capless fuel filler! I don't care how good they think their rubber seal on the filler door is... it will let in dust/dirt/water. I can't help but wonder why they went capless anyway... I am assuming to keep cost down, otherwise they would have to redesign a new filler door and box side to accomodate the addition of the DEF filler neck like Ford did. I'll bet they anticipate plenty of fuel contamination... keep in mind it is a large filter and it has a see thru seperator bowl so one can see the water in it. My opinion anyway. Crath

 

[EDankievitch]

That first filter is more of a water sep design from RAYCOR. Anything is better than what the earlier trucks had.

 

[gtobey]

Several of us commented about the capless filler door. It appears that any splashed DEF, snow, rain, dust, dirt, etc. will make it's way into the area above that flap and find it's way into the tank... .