1996 Ford F800 5.9 Cummins engine.

[greymouser7]

I have been working on my uncle’s Dump truck, and I am not a diesel mechanic.

I guess his workers drove around with the cap off of the fuel tank on dusty roads.

Replaced the primary fuel filter which looks just like an oil filter.

Replaced the primary fuel filter again.

Opened up the secondary filter screen ( some models have two screw on filters)

For some reason my uncle won’t take this to the appropriate ‘Diesel mechanic ‘ so he is paying me to fix it-am out of my depth a bit.

Replaced the lift pump, flushed the fuel tank twice, cleaned the screen filter, pumped up the lift pump at least 150 times including bleeding air out the top relief valve, and now I think got air in the injectors. It ran about 40 seconds. Does anyone have a paddle? This canoe is sinking & it smells funny.

 

[bcschief]

What does the inside of the tank look like if it's rusty you may want to replace it. Also I have seen cases were trash plugs up the elbow or other fittings in the fuel system. If it leaks fuel it will suck in air make sure no connections are leaking. I don't believe it has a filter sock in the tank.

Brian

 

[dukeboy440]

View attachment 1715353174 View attachment 1715353175 View attachment 1715353177 View attachment 1715353178 View attachment 1715353179 View attachment 1715353180 I have been working on my uncle’s Dump truck, and I am not a diesel mechanic.

I guess his workers drove around with the cap off of the fuel tank on dusty roads.

Replaced the primary fuel filter which looks just like an oil filter.

Replaced the primary fuel filter again.

Opened up the secondary filter screen ( some models have two screw on filters)

For some reason my uncle won’t take this to the appropriate ‘Diesel mechanic ‘ so he is paying me to fix it-am out of my depth a bit.

Replaced the lift pump, flushed the fuel tank twice, cleaned the screen filter, pumped up the lift pump at least 150 times including bleeding air out the top relief valve, and now I think got air in the injectors. It ran about 40 seconds. Does anyone have a paddle? This canoe is sinking & it smells funny.

As a former truck puller and employee of an aftermarket diesel company as well as Cummins themselves, the 5.9 is a ***** to bleed once starved for fuel. Being a 1996, that should have the P7100 series injection pump on it. What you'll want to do it, is get a helper, crank open( ie open the line a partial turn) 1 injection line where it goes to into the injector (by the head), have helper crank the start until you start getting fuel. Repeat the process 1 x 1 on each of the 6 lines. Worse case and yes, I know Cummins tells you not to do this, if it still wont start, fire it on ether, it'll sound like she'll explode, but she wont and she'll be just fine.

 

[teringer]

try running it out of a 5 gallon bucket ,that fuel tank will need to be pulled and cleaned and replaced check the pick up tube for blockage also look under the turbo on block for cracking a white crack leaking coolant I have seen many cracked after well used

 

[greymouser7]

There was a bleeder valve bolt(bolt within a bolt that had holes directing flow) that would not tighten down (it let air in the line), we took it to a shop and got it replaced, am heading back to the truck now, to pump up the fluid, crack & bleed a few fuel fittings, then crack the lines to each injector, turn it over, & blow the remaining air in the line.

 

[greymouser7]

try running it out of a 5 gallon bucket ,that fuel tank will need to be pulled and cleaned and replaced check the pick up tube for blockage also look under the turbo on block for cracking a white crack leaking coolant I have seen many cracked after well used

I flushed the tank with cleaners and a leaf blower twice. After running the engine 40 seconds, the secondary filter only had a few pieces of filth in it.

 

[brian6pac]

Wow what a mess, looks like someone put saw dust in the tank!

 

[greymouser7]

try running it out of a 5 gallon bucket ,that fuel tank will need to be pulled and cleaned and replaced check the pick up tube for blockage also look under the turbo on block for cracking a white crack leaking coolant I have seen many cracked after well used

The secondary filter was completely clogged.

 

[greymouser7]

What does the inside of the tank look like if it's rusty you may want to replace it. Also I have seen cases were trash plugs up the elbow or other fittings in the fuel system. If it leaks fuel it will suck in air make sure no connections are leaking. I don't believe it has a filter sock in the tank.

Brian

There were a few small rusty spots.

 

[dukeboy440]

There were a few small rusty spots.

Be careful with those Banjo washers, some they had copper and were good, if that has the brass with rubber seal, go ahead and replace those as they have a tendency to tear when re used

 

[greymouser7]

Half success! We got it running!
Now I got to deliver it to Gonzales, Texas.
Hopefully it doesn’t slow down again while running. Got blisters pumping up the lift pump.
THANK YOU GUYS!!!!

 

[dukeboy440]

Half success! We got it running!
Now I got to deliver it to Gonzales, Texas.
Hopefully it doesn’t slow down again while running. Got blisters pumping up the lift pump.
THANK YOU GUYS!!!!

If you wanna have some fun, remove the guide plate in the injector pump and watch her roll smoke like a dang volcano

 

[greymouser7]

Made it to Gonzales, Texas.
Mario Andretti would be happy to drive this truck!!

 

[RustyRatRod]

Made it to Gonzales, Texas.
Mario Andretti would be happy to drive this truck!!

Crap in the fuel system. I never wouldda guessed. <rolls eyes> lol

 

[greymouser7]

We checked the screen filter when we got to Gonzales Texas it was half full of dirt again. We definitely have to clean out the tank and probably the fuel lines again as well.

 

[RustyRatRod]

I'm glad yall got it to where it needed to be anyway.

 

[dukeboy440]

We checked the screen filter when we got to Gonzales Texas it was half full of dirt again. We definitely have to clean out the tank and probably the fuel lines again as well.

Drop the tank, completely drain it. Then remove the sending unit, get a shop vac and vaccum out the tank. If it’s a steel tank, it’s very possible it’s rusting from the inside out and if it is, just replace the tank