I fired up the rebuilt D4 7J yesterday for the first run in 3 months, fuel tank was half full, fuel pressure gauge was pegged in the green while cranking with the pilot motor, after firing the main motor up, I let it warm up for a few minutes, all was good, drove her out of the shed and didn't get even 40 yards before she died straight down, sounding like immediate fuel starvation.

I fired up the pilot motor again and cranked the main engine, the fuel pressure gauge was showing zero, not even a flicker, so I switched the pilot motor off while I went and got some more diesel. I filled the fuel tank, knowing it would gravity feed to the fuel tower given time, removed the fuel line and checked I had good fuel flow at the transfer pump, then opened both bleeders on the fuel tower, after awhile I had fuel dripping out of the lower tower nut, but not the top cover.

I then pulled the main fuel supply line out again, and removed the transfer pump valve housing, it was full of fine rusty trash from the fuel tank, the valve itself was lightly stuck to the main transfer housing, it's a new rubber valve, so I unstuck that, checked the spring, and put it all back together thinking I'd found the problem, a stuck valve and choked fuel gallery.

I fired up the pilot motor again, and after awhile had fuel dribbling out the lower bleeder, but not the top cap bleeder, even after 15 minutes of running the pilot motor at just above idle spinning the main motor on decompression, I still couldn't get any fuel, not even a spit, out of that top cap bleeder.

Is it possible for the 4 fuel filters to suddenly just get so choked up that no fuel will pass through them, or is there another reason that cap section at the top of the fuel filter tower is not getting any fuel? The filters in the tower have done about 30-40 hours work from new, but this tractor was a wreck when I dragged it home 10 years ago, so I wasn't surprised to find that fine rusty crud in the small gallery of the transfer pump valve.
Thanks
Mike

The tube in the filter housing from the transfer pump to the fuel gallery in the housing can get plugged also. Use compressed air and blow it out with filter cover off.

I would think you should have fuel spraying out of the lower bleed screw.

I can see how a tank that has grown some sort of crud could plug the filters that quick. My experience has been that the stuff is very fine brown to black powdery material that can coat a filter and plug it up in short order. It will usually stop mesh strainers and may even plug outlet spigots above the tank valve if the machine has such to prevent drawing the last little bit of fuel from the bottom of the tank.

Lots of JD equipment is set up that way with about a 3” tall extension pipe with slits down from the top an inch or so. Even though the top is completely open, I’ve run tractors that were severely affected that I had to blow back through the tank line to clear the crud off that spigot about every half hour. After a few hours of that, the time and effort to clean the tank seems to be a much more productive use of my time than it does the first time the line had to be cleared out!

Thanks guys, I'll drag the D4 over to my workshop so I can clean the fuel tower out better, right now the old girl is sitting in a 2 foot high hay crop!

Not good news sadly, I got busy and cleaned out the fuel tower and replaced the filters, I was expecting to find a lot of trash in the fuel tower but there wasn't much, I had cleaned it all when I first got the tractor running around 2014, and it had only done about 30 hours since, still, I can tick that box.

After trying to bleed out the system I could get fuel flowing out both bleeders on the tower, and the injection pump bleeders, but not develop any pressure, even after blowing air back the fuel line to the tank, and using some air pressure in the fuel tank to push fuel gently through the system, there was no change, so I decided I needed to pull the side cover off the fuel transfer pump to confirm the pump gears were spinning, when the crankshaft was turning, they were not.

This engine had a bent fuel transfer pump shaft when I dragged her home back around 2014 and was trying to get her running, and with Eddie Bedwells help at the time, we got the issue fixed. Eddie kindly made me a special tamping tool for fitting the new graphite impregnated shaft seals and gave me good guidance, these early D4 pumps changed design several times, so it was challenging trying to sort out the parts needed.

With the side cover of the transfer pump off, I could see the gears were not turning when the crankshaft was, and I assumed that maybe the transfer pump shaft had bent again, or a key had sheared, so I pulled the pump to investigate, only to find the pump shaft is OK, doesn't appeared bent, or key sheared, but with the pilot motor running again and spinning the main motor, I could see the accessory shaft is not turning, what are the chances of that for crying out loud!

To top things off, at the start of this problem solving journey, the pilot motor pinion has decided it will not release manually, no matter how hard I press the 2 latches in through the inspection hole, the pinion refuses to release, so every time I need to start the pilot motor it is fighting against the drag of the pinion clutch, what a pain in the backside, it's one thing after another, this tractor has only done about 10 hours work since a rebuild of both engines and back end.

So the big question is, I assume a key or pin has sheared on the accessory shaft drive, so the radiator and timing cover have to come off, but I'll also need to re-time the shaft once I get it all back together.
Thanks
Mike

Hi Mike,
What is your serial number as you know we need it to get the right pump shaft as there is 3 used in the 7J.

Here is the timing mark for the 4G and the early 7J up to 5103.



Regards

"Neil" wrote:

Mike, if your latches don't release, one reason could be that the adjusting screws are in so tight that the spring becomes bound before the latches can release. If so, pick up a new spring, and reset the adjusting screws back to flush with the cover, as an initial setting, or maybe one turn in if everything else is worn.

Yes, thanks Neil, I was thinking about you yesterday and your D2, I remember you talking about replacing your pinion spring.
Regards
Mike

"rax200" wrote:

Hi Mike,
What is your serial number as you know we need it to get the right pump shaft as there is 3 used in the 7J.

Here is the timing mark for the 4G and the early 7J up to 5103.



Regards

Thanks for the photo Daryl, that tractor is 7J1261.
Regards
Mike

Hi Mike,
it almost goes without saying that if you have found that the Accessory Drive Shaft is not turning then the Injection Pump is not turning also and seizure in the drive or pump may be the source of your sheared key--if that is what you find--check the Acc. Drv. Shaft front bearing for seizure, ditto the Injection Pump, its drive tang and slot for damage if pump is seized and also the Governor due possibly from low oil level in the Inj. Pump sump.
If the Acc. Shaft front bearing is seized check the oil supply and pipe work to that front bearing cage and that the bearing oil hole is aligned to the supply port.

Looks like front timing cover off to do most of this checking/repairs--not a nice job these icy mornings you are having at present.
Cheers,
Eddie B.