Good to know. I feel better about adding to rather than replacing the Ford filters.
There must also be a 12v connection for the pump somewhere.

 

"So did Ford make a change?"

I, for one, dont know, but that dont mean much.

 

AirDog® II Fuel Air Separation System featuring Demand Flow Technology

AirDog® II is designed to operate at flows and pressures beyond the maximum requirements of the engine. It receives fuel under vacuum from the fuel tank containing entrained air/vapor, particulate contaminates and unknown quantities of water.
The fuel passes through the water separator which removes the large particulate contaminates that could damage or jam the gerotor fuel pump. The fuel, with only entrained air/vapor and tiny particulate contaminates remaining, then enters the fuel pump.



I agree, though that it is not specifically designed for WATER removal....but talking to them directily....they say it does. That is why I would go with a Racor 500MA or a 900 in front of it.

The beauty of this system to me is that it has its own pump. which eliminates any issue with starving the DFCM of any required flow! It is preassure regulated to 10 psi factory.....and has 100-165 gph flow....so it will always have enough fuel at the suction side of the dfcm!


As far as the AIR is concerned, when your tank is full...not at all going to be an issue. IMO but once you have 1/4 tank gone...or more, I think the air will become more and more a possibility!

Think about how much your fuel gets sloshed around in that tank....

AGAIN, we come back to the "possibility" of a pump operating at it limits.... IF air is sucked into the line....it will be pushed through the pump! AIR does not make a good lubrication! Hence when you change the fuel filter you have to cycle the key on and off several times to purge the air out of the filter via the re-circulating system...it pushes the air back to the tank, but under power the system is sending fuel to the hpfp and any air bubbles that ARE in the fuel that get sucked up....will have a very good chance of going through the pump.

My gut feeling is that this hpfp failure is really a combination of things all weakening the pump surfaces. In some cases it has proven to be more than the pump can handle.

With the cost of repairs if it does fail.....Under $1000 to put a good filter sytem on that will not effect fuel flow at all! Thats is the choice for all of us to make and I do not fault ANYONE who doesn't think it is a good idea. Thats why we live in AMERICA, right!

 

I agree with your point and I think the Airdog idea is a great one. However I do want to make a point about air bubbles in fuel. When the fuel is pressurized it can hold more air in a dissolved state, meaning there are fewer or no air bubbles. So when the DFCM pressurizes the fuel (I think it's about 50psi), most of the tiny bubbles will probably disappear.

Think of it as the opposite of effervescense. When you open a pop can, you release the positive air pressure inside and air bubbles literally form out of nothing in the pop itself and percolate to the surface. This is because the reduced pressure on the pop cannot hold as much air in the dissolved state. If you were to pump more air back into the can, it will slowly dissolve back into the pop.

So when the DFCM pressurizes the fuel, most of the air bubbles will literally disappear. The same thing happens again when transitioning from the low pressure system to the high pressure system. The bubbles can no longer be sustained and they collapse upon themselves and dissolve into the liquid fuel.

My point is that although air bubbles may present a problem under certain situations, they will likely disappear after being pressurized.

-los341

 

Absolutely, to each his own. I think a Racor 500 or a 900 filter/separator will do the same thing as far as cleaning the fuel for a lesser price. Racor filters are abundant and easy to find. You also don't have to worry about another pump "breaking down". I do not believe the air in the fuel tank or in the lines is an issue worth trying to fix.

AirDog® II is designed to operate at flows and pressures beyond the maximum requirements of the engine. It receives fuel under vacuum from the fuel tank containing entrained air/vapor, particulate contaminates and unknown quantities of water.
The fuel passes through the water separator which removes the large particulate contaminates that could damage or jam the gerotor fuel pump. The fuel, with only entrained air/vapor and tiny particulate contaminates remaining, then enters the fuel pump.

From what I have picked up in all this, it is the emulsified water thats the problem. I imagine the OEM separator and filter does the same thing as AirDog lists above- "removes large particles". But what does it do with emulsified water?

But like I said to each his own. If you decide to purchase it be sure to let us know the results. As far as America I did my part and voted Tuesday!

Pretty soon the back of our trucks will be full of filter systems. To bad Ford cant put a fuel pump on it that will last the life of the truck in real world circumstances.

 

Good point!

I never gave that any thought. They disappear....but to what extent....are the microscopic air bubbles still posing a LOW LUBRICITY situation? It just may be the catalist in the bad US SCAR ratings as opposed to those in Canada. NO? Just a thought.

 

They disappear at a molecular level, meaning there are no air bubbles, or tiny pockets of air. The dissolved air molecules are evenly distributed amongst the fuel molecules.

 

Heh ..... my $0.02 worth. I would suggest being very careful in altering the filtering and/or fuel pump(s). It could be a recipe for disaster from an operational and/or a warranty perspective. Read pumpdoctors feedback on cavatation at the HPFP. There are also sensors on the fuel pressure leaving the lift pump and so on and so on. I just wouldnt want to see someone blow an HPFP and be denied warranty because of a change that made good sense in theory.

I investigated previously, (see other posts on AirDog etc.) and wont be doing it. That being said the post HPFP high pressure filter seems to have some merit on the surface. Better to defray a $12K to a $2K repair bill if possible. The trick on that one, aside from the HP fittings and such, is the issue of dealing with a clogged filter and how that impacts the injectors. Some have said there are sensors on the injectors that prevent damage but I'm just not sure.

 

Good luck to all of you.

I'm glad that some of you are wililng to be guinea pigs for a potential $10-18,000 engineering experiment.

I look forward to the final product...

 

While not at all the same as the 6.7 the 7.3s had issues with air getting into the fuel system mostly from bad hose connections.
I am concerned that just adding filters may cause issues with the stock lift pump as I assume the OP was.
B&L, The issue is that Ford has no clue as to what is causing the HPFP failures. Their excuse is water. Then they deny the warranty coverage. We are looking at possible ways to save the pumps in the first place. If Ford is going to deny the warranty anyway, we could prevent that $18K repair.

 

I don't think you have any way of knowing what Ford does or doesn't know about the HPFP failures. To suggest they have "no clue" is pretty far fetched I think.

I know what you're trying to do, however, you could also damage the pump, injectors, etc... in the process of modifying a very complex system and engine and end up with a big bill for your trouble.

Like I said, good luck to you all, if no one ever took a chance and tried to build a better mousetrap, we'd never move ahead. I just know that I won't be spending my money and taking on that risk.

 

I am new to this group, so forgive me if my reply doesn’t seem to jive correctly or in the order it should be. This is one of the best questions I have heard yet about micron filtration with respect to additives

 

The additives are in suspension with the fuel and sub-micronic in size so I can't imagine there is any practical single pass filter that would be able to pull them out of suspension and still flow anywhere near enough.

This is an interesting thread but about a decade old at this point. I do find it interesting that fuel filtration beyond the OEM doesn't seem to be as a huge deal in the 6.7 PSD world, it is more taking care of the CP4 pump. Coming from a 3rd gen 5.9 cummins, it is totally different the OEM fuel filters were wholly inadequate for that fuel system and upgraded filtration was very popular.

 

what warranty?

ford will always play the “you put water, rust, gasoline, def” in the fuel card.

I have the 125k/8yr ford extended and I decided long time ago I’d rather spend 400 for an s@s gen2 DPK now and then if in need a cp4 later, just buy the cp4 pump vs paying ford 10k + for them to install a fuel system disaster repair kit.