Lift pump

[Injector1]

I have a 2003 2500HD. I was reading a thread and it talked about a lift pump. Can someone explain to me what a lift pump is and how does it help my engine.

[brethl]

A lift pump refers to a electric pump that pushes fuel up to the Cp3 injection pump. In stock form the Duramax has the Cp3 doing double duty of sucking fuel from the tank and sending it to the injectors.
A pump like the Airdog also removes injector harming entrained air from the fuel. Hope this helps.

[Injector1]

Brethl thank you for the answer. That clears up the question.

[TOTHEMAX!]

Moved this thread to the Fuel upgrade section

[olemansmith]

I'm still a newbie, even after having joined over a year ago. I've only driven my 2003 3500 Crew Cab DRW 4,000 miles since I bought it. I had a free filter & oil change & nitrogen tire fill coming from the dealer, so I got that done two days ago. It had been 14 months since it's last change. It sits a lot. I drive it around home about once a month to keep it limbered up. I get on here and read, but seldom fully understand all that you guys say.

I think I understand that you guy's, in general, reccomend installing a lift pump for all LB7 trucks....right?

Heck, for all I know, it may already have one. I'm gonna climb around up under it today while its nice and sunny and try to learn some things.

If it doesn't have one, should one be installed upstream or downstream of the fuel filter?

I'm guessing the "lift"pump" delivers additional flow along with a little boost in pressure to supply fuel to the pump, making it's job easier and helping it to last longer. Having said that, I'm assuming its okay to install the pump right off the tank, upstream of the fuel filter along the frame somewhere.

I have one last question out of ignorance and inexperience. I hope it is okay to ask in this section of the forum.....Do the early trucks like mine have a noisier valve train (rattle) in them than the newer Duramax Trucks? My son thinks it's excessive, I really don't know. It is quite audible during acceleration, but not so much at cruise speed.

Thanks,

Eddie

[D.Camilleri]

You are on the money with the lift pump. Many people add them to keep up with fuel demands of big tunes. Others add them to simply make the injection pump last longer. For a mostly stock truck, Kennedy Diesel a vendor here has a very quiet long lasting pump with instructions on his web site. With your truck sitting a lot, I would use a injector cleaner fuel additive in your fuel. Power Sevice diesel klene in the grey bottle works well. Also adding some two stroke oil to the fuel helps quiet things down also.

[CaptD]

Lift pumps are installed as close to the tank as possible.... older dmax engines are noisier than newer ones.....

[labmouselb7]

the Lb7s have a bit higher compression ratio and a few tuning differences than the newer one and are a bit louder. You may notice some of the injector type noise quiets down when the rpms get above about 2800 or so just before the shifts. this is normal for the earlier engines.
I know drive an 06 with an LBZ and it makes about 1/2 as much noise as both LB7s that I owned.

[olemansmith]

Thanks guys for clearing up some things for me.

I crawled all up under it this afternoon and it hasn't had a lift pump added. All I saw was what looked like a "fuel cooler" right in front of the tank for the return fuel and also, what I think must be the ABS control module.

I did discover that it won't be too hard to swap the fuel filter out when it is time to do that....by the way.....when do you change the fuel filter???

Dumb-ass me...still haven't bought a spare to carry with me !
Guess I'll buy a GM. I ain't savvy enough to guess for another brand. I've heard of WIX all my life and I know they use them on big over the road rigs, but I just ain't sure for my truck. I don't think I can go wrong with a GM...can I?

As for the oil:
The dealer used 10 qts. 15W40 Bulk Goodwrench Oil (invoice) with a FP number 7202 filter (invoice), that may be a NAPA Gold filter...I saw it today, it's black.

I'm old...and I'm new to this, and I don't understand all the synthetic, 4 micron, 10 micron talk, so I'm thinking, I better just ask for what it came with.

I need to get busy studying maintenance schedules for this truck. Thanks for all your responses and valuable insight from all of you. I really appreciate it.

Eddie

[RDS]

Here is the lift pump and filter setup I made for my '02 using a Kennedy Diesel lift pump. Just click on RDS and then my profile and you should be able to see a picture of it. The filters are actually Donaldson PN P550847 for fuel filter/water separator-PN P551313 for the fuel filter. Very reasonably priced, too.

Rich