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Discussion Starter #1
I have a Kennedy lift pump I am moving over to an LML I just picked up. After doing the custom bracket for the pump and filters and trying to get it nice and tight up against the cab floor I realized that the pump is higher than the tank. What keeps the fuel from bleeding back on a Duramax? I don't want to get air locked in the pump being higher every time I shut it off. Does the pickup-tube have a check valve or something in it? Thanks guys.
 

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Centrifugal pumps are terrible at drawing fuel. The pump should be as low as possible.

That said... once the system is bled, the only way for the system to lose prime, is for air to enter somewhere.

You could have the pump on the roof, but as long as the system is air tight, it doesnt matter.
 

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I don’t believe there’s anything on the factory system but it would be easy enough to add a small inline unit if you wanted too just for piece mind.
 

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The fuel filter under the hood....it's above the tank.
Oh, the horror. :teehee
 

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Discussion Starter #5
Here is John Kennedy's response to my question:

I would not do that. I would also not do the filter thing. The first question I ask when a customer calls about issues with my pump(s) is do you have any filters mounted near the pump?

Trying not to be an ass about it, but people always want to reinvent the system. Water separators don’t work. I’ve never seen anyone regularly remove water from their drain.

John Kennedy
Kennedy Sales and Service
W3567 26 Rd
Loyal WI 54446


Not sure I agree with this at all......
 

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Here is John Kennedy's response to my question:

I would not do that. I would also not do the filter thing. The first question I ask when a customer calls about issues with my pump(s) is do you have any filters mounted near the pump?

Trying not to be an ass about it, but people always want to reinvent the system. Water separators don’t work. I’ve never seen anyone regularly remove water from their drain.

John Kennedy
Kennedy Sales and Service
W3567 26 Rd
Loyal WI 54446


Not sure I agree with this at all......
What is this filter thing you want to do ? I have over 450,000 miles on my van and I have never once drained a filter. I always just check for restriction and change as needed.
 

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Here is John Kennedy's response to my question:

JK said:
Trying not to be an ass about it, but people always want to reinvent the system. Water separators don’t work. I’ve never seen anyone regularly remove water from their drain.
Not sure I agree with this at all......
And yet, he uses the feature as a selling point for his overpriced Mega aux filter kit, that looks to be a major PIA to change the filter (and you thought the stock one was a hassle).
https://www.kennedydiesel.com/detail.cfm?ID=241

JK site said:
Built in drain to aid in servicing, and allow periodic sampling for water.
I've found water in my drain sampling on the (Baldwin BF1233) aux FWS filter.
Also, there are instances when you will have your WIF warning appear in the DIC.
 

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Discussion Starter #8
Right? And he says not to have filters around the pump, but it is ok if you put an extra mega-filter up front under the airbox to catch the coldest of windchill in the winter running down the road. I don't understand that theory at all. I was going to add a BF1212 before it and a Donaldson filter after it. You guys see anything wrong with that? I was just worried about the pump being up so high. Didn't know he was going to crush all my dreams..........
 

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Right? And he says not to have filters around the pump, but it is ok if you put an extra mega-filter up front under the airbox to catch the coldest of windchill in the winter running down the road. I don't understand that theory at all. I was going to add a BF1212 before it and a Donaldson filter after it. You guys see anything wrong with that? I was just worried about the pump being up so high. Didn't know he was going to crush all my dreams..........
I would keep it simple by going with a 10 micron filter after the pump to stop the big chunks then a quality filter like a Racor in the factory spot.
 

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10 micron FWS before the pump, not after.
 

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10 micron FWS before the pump, not after.
With a Kennedy pump you want to go after as to not starve and burn up a pump. As the filters start to load up the pump can continue to push through the filters you keep you going.
 

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Discussion Starter #16
I would keep it simple by going with a 10 micron filter after the pump to stop the big chunks then a quality filter like a Racor in the factory spot.
That wouldn't make the water separator very effective at catching water after the pump emulsifies it would it?
 

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That wouldn't make the water separator very effective at catching water after the pump emulsifies it would it?
Like I said in another post I have done it this way for 250,000 miles with zero issues. Just look at all the people that have installed Kennedy pumps and use only the factory fuel filter and they have no issues either.
 

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That wouldn't make the water separator very effective at catching water after the pump emulsifies it would it?
The churning and bypassing and churning and bypassing some more in Fass and A/D set ups is what emulsifies water into the fuel.

The Kennedy takes the fuel from the tank, and gives it a gentle shove towards the CP3 or 4, and thats it.
 

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Discussion Starter #19
After rethinking all of this I think I will run the pump down below by itself and the Racor or Baldwin BF46062 in the stock location. This will be easier on the pump and should keep the CP4 and injectors happy going down to 4 micron. This with a good additive for some lubricity and I should be protected from the CP4 bomb. Thanks for the help guys!
 

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With a Kennedy pump you want to go after as to not starve and burn up a pump. As the filters start to load up the pump can continue to push through the filters you keep you going.
While the logic sounds good, it doesn't hold up in real time pressure testing I've done. The filters involved have very little pressure drop. The CP3 can pull thru 3 filters with NO lift pump involved. It's doubtful the little JK pump would be strained, routing it one way or the other.

The pressure drop between a fresh filter and one that's at end of life is only 2"Hg. It will work either way, before or after. But a FWS filter is most efficient when the fuel is pulled thru it, not pushed (per Baldwin). This is how your stock fuel supply is set up.

When you do add a LP, including an aux filter head for a FWS before the pump, maintains that efficiency, and greatly improves the life of the under hood filter, which is now your secondary filter. One from being downstream of a 10m filter. Two, positive pressure thru the stock filter will utilize more of the full media, with no voids left, which you'll find under vacuum use.

Height location isn't much of a concern. Per JK, what kills the pump is trapped air from not priming properly. It leaves tell tale internal wear marks seen when they open it up for warranty. And he states that if they find those wear marks, any warranty is voided.

Summation; there's no wrong way to mount one, just a better way than others.
 
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