On a recent trip with my 94 F350 7.3 idi hauling a small tractor, I found that truck struggled desperately to climb any hills. I was told by tractor mechanic that truck needed the lift pumps, that they're are 2 or more. How do you find the location of these lift pumps?
In the end, i broke down ...the truck died while driving 65mph. I had 1½ tanks full of fuel. Recently, i had both tanks taken out , emptied, cleaned out and refilled with new diesel and fuel pump replaced. Besides the lift pumps and locations , what else should I replace at this time? Any suggestions would be greatly appreciated.

 

First thing you need to replace is that tractor mechanic lol. There’s only one lift pump that feeds the injection pump. Passenger side lower down of engine is the lift pump. Follow the steel fuel line from your filter down into the deep dark depths and you’ll see it. Make sure the new one comes with a gasket, and tip the arm all the way down into the block before putting it in. You want to be under the cam lobe not over it. Search around on here, there should be pics and more details on other threads so you can see what goes on

 

Senior User, thanks so much for sharing your knowledge!!

 

If your lift pump is original, the new one you get today might have a different angle on the pump arm tip. Don’t worry about it, that’s just how they come now. Just make sure you tip it all the way down in the block, then shove it in and bolt it up so your under the lobe. Might be some resistance when bolting it up as the arm will compress, that’s also normal.

 

I think I would try to run some tests before you turn it over to a mechanic, I can't imagine how much they charged you to drop and clean your tanks ??? did they replace your fuel pick up shower head ??? they have a known history of failing in the tank,

how long have you owned the truck ?
how many miles are on it ?
Do you know any of the maintenance history ? last time the IP or injectors were changed ?

did you have to be towed home or were you able to get it started ?

when you say "struggling on hills", how long a steep of a grade or are you just running around on local streets ?

is this still the first 1/2 tank of fuel since the cleaning or have you run a few tanks through it ?
you could easily press the schrader valve at the fuel filter fitting to see if fuel comes out while you crank it,
did you see any smoke out the back while it was struggling up hill ?
I would normally guess you were getting some air intrusion under load

There's a great write up somewhere here ( I believe by genscripter) about easily setting a fuel can up on the front bumper to help isolate where your problem is,

 

Good diagnostic information. In my case the lift pump is very obviously leaking and needs replacing.
What I have not found in any forums is what to expect when you unbolt it? Is there a bunch of oil inside the block that’s going to ooze out all over the place? Or anything else to look out for?
New to this 7.3 IDI beast, lots to learn!
thanks

 

LeadLearner, you said here:
Recently, i had both tanks taken out , emptied, cleaned out and refilled with new diesel and "fuel pump replaced."

What Fuel Pump did they replace? There is only one.
90Ford73 think you missed that part. great write up though.

If the Lift Pump died, and if that is what was replaced, wonder why they thought
the tanks had to be dropped and cleaned out?

There is a 3/8" rubber feed line curly "Q" hose that connects to the Lift pump.
Hope it was replaced at the same time.
When I replaced my LP, that hose was hard and cracked.

When the steel line to the Filter was removed, the fuel would have drained out.
I would have filled it before attaching to the filter end, cuts down on air into the
System.
Both ends of the steel line have a seal refered to as an "Olive". I replaced it with
a rubber 3/8" hose and 2 Brass Barbed fittings. Didn`t want to deal with the olives.

You can push in the Shrader Valve on the Filter Head as the engine is being turned
over (by your lovely assistant) put a rag over the valve as Diesel will shoot out of it.
Cuts down on making a mess.

I think you got took with them pulling both tanks and cleaning them out.
I pulled the bed on the 86 in 2019 to install a 38 gal tank in the rear.
Pulled the Sending unit on both tanks to replace with a new one, and both
tanks were squeeky clean except for the broken Shower heads.
Truck was 33 years old at the time.
Think you paid for labor and fuel unnecessarily.

Keep us posted where you are at.


Charlie

 

Kyle92Dullay, you will not get any oil except that might be on the Pumps arm
dripping off. The Oil level is below the Pump.
If you have access to a pressure Washer before digging into it, will help. Blow out
all the krap, less to get into the engine....and nicer to work on.
Place a pan under it just incase.


Charlie

 

Charlie, the OP has not been back since his first posts back in April.
Kyle, as said no oil will come out of the block, unless the lift pump leaked inside and filled the block up with fuel.
as Charlie said, a pressure washer will make the job much easier once everything is clean.
hint for putting the new pump in:
i always hold the pump body up a bit when stabbing the arm in the block, than tilt it down to meet the mounting surface and putting the bolts in.
this ensures the pump arm will go under the eccentric. if you just stick it in the hole and the arm goes over the eccentric, the pump will not work and could possible snap the arm off the new pump.

 

Thanks Charlie and tjc for the clearer picture on what to expect. I figured the oil level would be lower than the LP, but it was worth asking.

 

Just reme.ber.

The only stupid question is the one you don't ask.
We are not all perfect and all knowing..
if we were,, we would be politicians.

 

Got that one right Tom, and......
Todays 18yr old`s have the mentality of a 12 yr old a decade ago.

There is nothing any of us know that we didn`t learn from some one else.
I will be 79 on Sunday, and Iam still learning.
Mind is like a Parachute only works when open.

Kyle, welcome to the Forum, and keep asking away.



Charlie

 

Just a quick update. I finally unwrapped our F-350 for the spring/summer and the first todo on my list was getting the lift pump replaced before batteries went back in or attempted firing it up.
The job went pretty smooth, had to remove the alternator and bracket to get some working space. Not a big deal. It gave me a chance to polish up everything I took off.
Removal and clean up was easy enough, just took time. Largely due to my slight lean towards perfection. The engine block gleamed before installing the new pump. Unfortunately only around the area of where the pump attaches.
Installed pump arm into the block, angled down as suggested, only a little resistance getting the surfaces and bolt holes lined up. Installed new curly Q fuel line and steel line to the filter (filled these with diesel with syringe before installing). Reinstalled alternator, batteries and waited 24 hours for RTV to harden.
Then the moment of truth, and severe apprehension. I bumped the starter relay to get a little air out of the lines and listen for a big snap of the newly installed fuel pump arm. Thankfully no snap!
I climbed in the drivers seat, installed the key wondering how long I was going to have to crank and crank. Stared endlessly at the Wait to Start light...
Little did I expect the crap to be scared out of me when the whole thing fired up with the first flick of the key into start position.

It's now been a couple of weeks and I can not believe how well it starts now. May dad even allows me to part on his driveway again as there are no more leaks!
Moving on to the next item on the endless todo list.
Many thanks to everyone's posts and assistance
Kyle