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I have a few questions about adding the Kennedy lift pump. I called a couple of diesel shops in my area and asked if they installed a lift pump on my truck, would that help the CP4 to last. Both shops said no. I do have a Nicktane adaptor and use the Donaldson fuel filter plus the Nicktane auxiliary fuel/water filter. Do you guys think the Kennedy lift pump will help the CP4 to last longer? If so, how does it help? Other than the filters, my truck is stock.
 

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I'd call Kennedy and ask him, he's a straight shooter.
 

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Kennedy has made the statement more than once that all Duramxes should have a lift pump. If you research some of his comments, he elaborates on his reasoning.

Whether or not it will save a CP4 may be debateable. Most of the issues with the CP4 were due to the ceramic piston failing and the coating not being able to withstand the higher wear induced by ULSD here in the states. You may benefit more from running a good additive or running a biodiesel.

However, a lift pump is certainly going to help with additional filtering and water separation, which is good. It will certainly keep positive pressure in system and cause the CP4 to work easier, and it will keep air out of the system which can also cause issues with injectors.................all good!

I am not brand partial, but I did just buy the new Air Dog II 4G cause they were on sale. This corrects some of the past reliability issues that some had and adds some new features. Lot's of fuel filter options. By the way, contrary to what people say, I am sure this unit will pass fuel if the pump were to fail.

AirDog® II-4G - Advancing AirDog® Technology by Removing Entrained Air/Vapor from Diesel Engine Fuel

Kennedy's system is well regarded and is the most economical, perhaps a little harder to install without the quick connects.
 
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Discussion Starter #44
I ordered up the air dog ii 165 and installed it this weekend. Fairly simple, took only 3 hours to get it the way I liked it. I trimmed all the hoses except the supply to the motor. I'm debating on not using the stock steel line and running it right up to the motor.... Any thoughts on that?

Otherwise, I lightly coiled it up and used the steel line for now. Super quiet once the truck is running, not even heard. Quiet right before it starts too. You can hear it, but barely. I also have a stock filter delete kit to install next weekend.
 
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I ordered up the air dog ii 165 and installed it this weekend. Fairly simple, took only 3 hours to get it the way I liked it. I trimmed all the hoses except the supply to the motor. I'm debating on not using the stock steel line and running it right up to the motor.... Any thoughts on that?

Otherwise, I lightly coiled it up and used the steel line for now. Super quiet once the truck is running, not even heard. Quiet right before it starts too. You can hear it, but barely. I also have a stock filter delete kit to install next weekend.
Did you install the new 4G model? Did you drop the tank? I am going to do mine this week when my tank empties. I was looking at it this weekend and with my lift, I can get to the tank pretty easily. It looks relatively easy to drop, except for the filler tube connection. I am going to try it without the tank drop first.
 

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Did you install the new 4G model? Did you drop the tank? I am going to do mine this week when my tank empties. I was looking at it this weekend and with my lift, I can get to the tank pretty easily. It looks relatively easy to drop, except for the filler tube connection. I am going to try it without the tank drop first.
Hint for you guys, leave the filler neck hooked up. Remove the fuel cap and put a rag or paper towel in the hole, unbolt it from the plastic-3 7mm screws and undo the ground, 10mm bolt and just manouveur it all out.
 

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Good info!
 

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Oops, sorry, this was for earlier GM models, not sure about the 2015 but its easy to see if that apply's.
 

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I was looking at the filler hose today and it is the same connection as previous models. That being said, there is plenty of clearance above the tank to make the connections without dropping the tank.

The directions are a little dated and only include pictures of the 2009 truck. Thoroughbred Diesel has a video that is a great supplement.

https://vimeo.com/51928736
 

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I think I am going to add a 8.5" wide x 10" tall sheet metal piece between the pump bracket and truck mount to act as protection for the filters. With my lift, I think the filters are going to be pretty well exposed behind the front tires. doesn't look like debris is hitting the tank guard now, but one piece of debris and your day is ruined.
 
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I am Todd Form T&C Diesel, I've seen the CP3.4 last form 15K to 380K miles, The CP3.4 is just not the robust design of CP3s (over 30 different configuration's) The CP4 is used on many vehicles Ford, GM , Ram 3.0 and others.

Water is the big killer of all HPCR pumps, contaminates are 2nd, and Poor volume would be 3rd. Filter labels are so mis-leading I would get banned if I posted the truth on the procedures used to rate Filters ( Most re-badged filters are rock catchers only)
The CP4 has 3 main bushings Cam ,Tail and Front, the tail bushing takes a beating and eventually the trim will get out of spec and self destruct the pump.

You can add to the life of this pump (CP4) by keeping your fuel tank full in summer heat, the fuel cools this unit.
 

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I am Todd Form T&C Diesel, I've seen the CP3.4 last form 15K to 380K miles, The CP3.4 is just not the robust design of CP3s (over 30 different configuration's) The CP4 is used on many vehicles Ford, GM , Ram 3.0 and others.

Water is the big killer of all HPCR pumps, contaminates are 2nd, and Poor volume would be 3rd. Filter labels are so mis-leading I would get banned if I posted the truth on the procedures used to rate Filters ( Most re-badged filters are rock catchers only)
The CP4 has 3 main bushings Cam ,Tail and Front, the tail bushing takes a beating and eventually the trim will get out of spec and self destruct the pump.

You can add to the life of this pump (CP4) by keeping your fuel tank full in summer heat, the fuel cools this unit.
Now there is some good information! :thumb:
 

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I forgot to add, depending on use ,Re-bushing the pump will extend its life, I know its a hassle to remove. If this pump is freshen up at 200K-250K it will last, The front seals leak at about this range also, The Ford version has more problems BC it does not have a GP (Gear pump) mounted on the rear, its internal lubrication is dependent on the external lift. The pump itself will meter more combustion fuel incorrectly (Ford) if the lift system is restricted or restrictive.
 

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Finally, someone with a reason why the Ford seems to have more problems.

Thanks.
 

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Discussion Starter #55
So I installed my air dog ii 2 weeks ago. Since installing it, the last 3 fill ups have been over 20mpg. Does this seem odd to anyone? Before I was 16-17.5 and my driving nor commute has changed.
 

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Warmer weather?
 

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Discussion Starter #57
I would think that, but I've never gotten that good of mileage before. Also, warm is a relative term Haha... It's been 45-50! Much better than the 0-20 from 2 weeks ago
 

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So I installed my air dog ii 2 weeks ago. Since installing it, the last 3 fill ups have been over 20mpg. Does this seem odd to anyone? Before I was 16-17.5 and my driving nor commute has changed.
Was it a fluke? are you still getting that kind of mileage? Maybe because no air is getting to the INJ pump, that is helping mileage. That is a big jump though.

bowz
 

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Just got my 11 back from cp4 failure. Dealer had it for 7 days. They had to take the cab off the truck to get to it, so I'm guessing you dont wanna do this in your garage. Cost was close to $10K to replace the whole fuel system due to metal from the pump going through the system. Not a fun fix. Thank GOD it was under warranty.
 

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