Does fuel go from Tank -> pump -> filter OR tank -> filter -> pump?

[Loco_Hosa]

M1009 has been parked for a year while getting axle swapped and 52 inch front sprins, shackle flip, ext. Finally went to start it and see it move under it's own power and something is really... Strange.

Something is completely blocking the fuel line between the tank and filter, as best I can tell. I pulled the filter box off and tried to send air backwards into the tank and was met with complete resistance.

Ok, so I pull the line off the tank, try to send air directly to the filter housing. Same result, completely blocked.

What is the path from the tank to the filter?Ran when I parked it, any ideas? Am I going about this all wrong? I ran out of time to fiddle anymore tonight.

 

[cucvrus]

From tank to right side of engine fuel pump via rubber hose attached to fuel pump. Exits fuel pump via 3/8" steel line and travels front of engine exits metal line via rubber hose to fuel filter and exits fuel filter thru 1/4" line to rear of injection pump. Travels thru delivery lines to nozzles and nozzles are connected to each other for the fuel return that returns on the front right side of engine. Then the return line returns fuel to the tank again. Check pick up sock in tank and all hoses on right frame rail. kinked or broken fuel lines are possible. Rusted off steel lines are also possible. Good Luck. Report Back.

 

[Loco_Hosa]

From tank to right side of engine fuel pump via rubber hose attached to fuel pump. Exits fuel pump via 3/8" steel line and travels front of engine exits metal line via rubber hose to fuel filter and exits fuel filter thru 1/4" line to rear of injection pump. Travels thru delivery lines to nozzles and nozzles are connected to each other for the fuel return that returns on the front right side of engine. Then the return line returns fuel to the tank again. Check pick up sock in tank and all hoses on right frame rail. kinked or broken fuel lines are possible. Rusted off steel lines are also possible. Good Luck. Report Back.

Perfect, this morning I had a little bit of extra time and I was able to pull the hose off of the fuel pump, and I verified there's no obstruction between the fuel pump and the fuel filter.

Now I just need to find the obstruction between the tank and the pump. I do not believe it's the sock, since I cleaned that when I had the tank out. Wondering if I accidentally kinked the hard line.

 

[TGP (IL)]

"I was able to pull the hose off of the fuel pump, and I verified there's no obstruction between the fuel pump and the fuel filter."

FYI,
The hose on the fuel Lift pump (right lower corner of the engine) comes from the tank.
The steel line on the same pump goes to the filter with a hose at the filter as mentioned.
Tom

 

[Loco_Hosa]

"I was able to pull the hose off of the fuel pump, and I verified there's no obstruction between the fuel pump and the fuel filter."

FYI,
The hose on the fuel Lift pump (right lower corner of the engine) comes from the tank.
The steel line on the same pump goes to the filter with a hose at the filter as mentioned.
Tom

Yup, pulled the rubber off the hard-line, put some air to it, fuel came out of the filter bleeder effortlessly. Pressurised the tank and nothing came out of the hard line at the pump.

I should have explained better o.o

 

[cucvrus]

I will argue that point. The rubber hose that runs to the fuel pump is the line that is sucking from the fuel tank. If you pressurized that rubber fuel line back at the lift pump and air bled from the fuel filter. You have some serious issues. The steel line runs from the pump up the right front of the engine and feeds the fuel filter. This much I am 100% sure of. Pressurizing the tank will push fuel out the rubber hose at the lift pump. You can put 100psi in the tank and no fuel will come from the hard line. What am I missing here. Get a fuel can hook a long rubber line to the barbed connection of the fuel pump and start the truck. Is it possible the fuel pump is bad or the incorrect one. I have seen the incorrect pumps in the past. Good Luck. Report back.

 

[Loco_Hosa]

I will argue that point. The rubber hose that runs to the fuel pump is the line that is sucking from the fuel tank. If you pressurized that rubber fuel line back at the lift pump and air bled from the fuel filter. You have some serious issues. The steel line runs from the pump up the right front of the engine and feeds the fuel filter. This much I am 100% sure of. Pressurizing the tank will push fuel out the rubber hose at the lift pump. You can put 100psi in the tank and no fuel will come from the hard line. What am I missing here. Get a fuel can hook a long rubber line to the barbed connection of the fuel pump and start the truck. Is it possible the fuel pump is bad or the incorrect one. I have seen the incorrect pumps in the past. Good Luck. Report back.

Our miscommunication I believe, is that you are picturing me removing the rubber hose from the fuel pump. I removed it from the Hardline.

At the fuel pump there is a short section of rubber line, it was easier to remove [from the top] the hose from the hard line that runs back to the tank then from the pump.

The Hardline, where it would usually attach to Rubber, and then go to the fuel pump, is where I expected fuel to come out when I pressurize the tank. It did not.

I then put air to the rubber hose, which is only a few inches long and attached to the fuel pump, and air came out of the fuel filter housing.

If I were to take a double Barbed fitting, attached to the rubber line at the fuel pump and a line going to a fuel can, I'm fairly sure it would start.

 

[sneekyeye]

Honestly what I would do at this point if it were mine is to run a new hose from the intake of the mechanical pump into a can of fresh diesel and see if it even pulls.
Then run a hose from the return back into the same jug.
Heck, it might even start right up if it pulls it in.

Just take the gas tank out of the equation.

 

[nyoffroad]

I'm going to toss my 2 cents in here, IF (notice the caps)I remember correctly there is a check valve built into the lift pump to keep fuel from draining back to the tank that would also block the air from blowing BACK to the tank. If that valve is stuck it might block it both ways. But remember this is a big if and based on my faulty memory!

 

[Loco_Hosa]

Well, busy week and havn't been out in the shop much. Tonight I started by checking the hoses on the top of the tank and found that I had kinked the fuel supply line. Cut it to the correct length, got it installed correctly and unkinked.

Little work purging the fuel system and it's running now. Tomorrow it will be outside for some photos.

Thanks everyone!

 

[cucvrus]

Same reason I remove the bed on the pickups to service the fuel tank. Not so easy on the M1010 but remember I never kept an M1010 as an M1010. I made a pickup plow truck out of them.

 

[Loco_Hosa]

Same reason I remove the bed on the pickups to service the fuel tank. Not so easy on the M1010 but remember I never kept an M1010 as an M1010. I made a pickup plow truck out of them.

Yeah, while doing this one I kept thinking, ”this would be much easier with an inch or two of body lift!”

At work all the trucks have a hinged door above the fuel tank for this stuff.