Most small diesels have a mechanical lift pump to feed the injection pump. If your engine has one I would check the pressure it's putting out, should be around 5-9 psi. If it has an electric lift pump some have a screen on the inlet side that can clog with algae that can grow in diesel fuel.
The filters being only half full when you take them off tells me it's a fuel problem. Also checking the/for a vented fuel cap is an excellent suggestion.

If you have a bad hose or fuel filter casting it would leak under pressure MOST of the time.

Is the fuel tank mounted above or below the engine?

About the same level. The filters are definitely lower than the tank.

Okay, here's my two cents worth...
I had a 980C Cat loader at a project I was running and it would do the same thing, run for about five hours then act like it was running out of fuel. We tried all the other stuff (filters, clogged vent) but it turned out that the pickup tube that goes down into the tank had a crack in it about two-thirds of the way down. While the tank was full, it covered the crack, but once the level in the tank dropped, it would suck air through the crack and the suction, or prime was lost, resulting in a big, dead machine in the middle of the jobsite....as usual it took forever to find the problem and minutes (sort of) to fix. Normally there is a plate on top of the tank that the hard line (pickup tube) runs through that you can unbolt and pull the tube up out of the tank. Sometimes you can see the problem as the crack will almost always run lengthwise on the tube and usually along the seam, but if you can't see it, pressure test it. Good Luck.
DST Ooopss, just saw the part about the tank being above the filters;does that mean the fuel line enters through the bottom of the tank? If so, I take it all back...all of it...

Since the tank is about the same level as the engine that means there is a fuel pump. Some small engines have the tank mounted above the engine and use gravity to feed the injection pump.
You mentioned earlier that the temp gauge did'nt work and possibly the engine was running hot. Engines will definetly shut down if contiually ran while overheating, but you would have the coolant boiling over. The engine would start to loose power and get sluggish then shut down. If you tried to crank it over it would'nt turn over because it's seized. After it cooled down it might crank over and start or stayed siezed up. If it did restart most off the time you would have other problems with the engine like: knocking, smoking, coolant in oil, or oil in coolant from blown head gasket(s).

I don't have experience on Case or International diesels. See if you can locate the lift pump on the engine. Sometimes their a mechanical pump just like a car when they have a carburetor, other times they are a plunger type mounted right in front off or with the injection pump. Some plunger types have a hand pump on them to prime the system after changing the filter(s). I have a friend that had a boat that did the same thing, after getting it running again you had to keep the engine rpm's under 1200 to keep it from shutting down again and limp home- it was a bad fuel pump.
Some things you can try are next time you use the machine loosen the fuel cap to see if its a bad cap. Also I would take off the fuel lines and blow them out with compressed air into a rag to see if theres any gunk in them. How do the fuel lines look? Metal- any kinks, rubber- cracked or swelled up.
Do you have or can you get a engine manual for the machine?

I didn't work on the thing today because I had a lot of Christmas-related stuff to do and was only at the Museum for an hour or so. I did take some pictures of the machine to give y'all a better idea of what I'm talking about.


This shows the two fuel filters and the injector pump. As near as I can tell this is the only pump in the system. The braided hose at the left carries fuel from the downstream end of the filters up to the pump. The choke cable going to the square lever thingy is the engine shutoff. The throttle is the linkage at the very top of the picture. The small yellow pipes coming out of the right side of the pump housing are the injector lines.


This is the back of the tractor. The fuel tank is H-shaped. There's a rubber crossover balance line at the bottom of the tank, it's the black hose that crosses over top of the PTO. There appear to be two fuel lines coming from the bottom of the tank; one from each leg. The one on the right has a petcock which will turn but doesn't seem to drain anything. One may be a return line, if so I don't know which is which. I can't trace the lines too well because they pass under the seat. When I have time to get dirty and really fool with it I'll pull the seat and see what goes where.

At this point I'm tempted to drain the fuel and replace ALL the fuel lines. I can turn a wrench and I know the basic princples that infernal combustion engines work on, but I'm not really a mechanic. I appreciate all the suggestions so far.

After seeing what the fuel lines look like, I would be inclined to replace them too. As one person said before, it may be the vent on the fuel fill cap is not functioning properly. One way you can check this is to not put the cap on completely tight. That is assuming the fill cap is a tbreaded type rather than a quarter turn. Then run the machine to see if it will act up.

When I am dealing with fuel lines, I like to use lines that have the connections crimped on the ends rather than using hose clamps. This will ensure that the connection between the hose end and the hose is tight, as long as the end was properly crimped on. It will also give it a cleaner apppearance. I do know that some older machines were set up to use hose clamps from the factory though.

Matt, I could'nt get the photos to load today, but I saw them a few days ago. The hose on the bottom of the tank would be a crossover the petcock is probably a shut off.
I would get a drain pan to put under the tank and remove the hoses on the bottom. Then get a stiff piece of wire and poke it up into the fittings on the bottom of the tank to see if any crud or rust comes out. You may find when you take them off that hardly anything comes out or one may be clogged. Also with the hoses off take the fuel cap off and see if the flow of fuel coming out increases.
Also all the return fuel lines I have seen goto the top of the fuel tank.
I have seen alot off old rubber fuel line that has swelled up over time from diesel fuel. Also that braided fuel line going to the injection pump has rubber inside that may have deteriorated. internally the rubber can break off and get into the system.
You said the tank is H shaped, is there a fuel cap for each side or just one? If there is just one fill then the tank is probably connected on the top. What may be happening is one side off the crossover is clogged and you run off one side until its out of fuel.

My server went down a couple times last week, once because of problems with my cable modem and once because the whole town's Internet access went down. Sorry about that. You should be able to get the pix to load again now.

The fuel tank was off the machine about 9-10 months ago -- we had to remove it to get to the right rear axle bearing, which disintegrated while I was cutting brush last winter. The tank was thoroughly cleaned at that time. The crossover line has been removed often, that's what I use to refill the filters when the thing quits. The crossbeam of the "H" conects the top and the crossover line connects the bottom. The filler cap is on the left side, visible in the picture.

I've about decided that my next project when I get some time is going to be to replace all the non-metal lines on the tractor and see if that helps. If not I'll have a look at the metal lines.

Replace the rubber feed line to the filter head. The injector lines are good ( no leaks shown in the photo). The problem is before the injection pump. Contaminted fuel or fuel line restrictions will cause this problem. The tank was cleaned so rule out the contaminated fuel. The feed line could be collapsing causing a restriction.

Did you check the lube oil level in your injection pump? It may be low, and causing something in the pump to bind after running for some time?

Just a guess, often owners don't realize injection pumps are not connected to the engine's uil system and require separate maintenance.

Good luck!

Steve Hunter
Cardinal, Ontario

Steve,

I doubt that that one has an independent oil reservoir, too small. Also it looks like the Lucas / CAV that is on our RMC Ballast Tamper (Continental diesel engine), an amount of the Lucas / CAV injector pumps use the diesel fuel as the lubrication oil.

Along your thought line, though, if the fuel is getting too hot, then it will thin out and not lubricate the pump correctly, and causing components to expand and bind.

Also the machine could be telling scrmcurator that it is getting time to rebuild the pump, afterall when the fuel is cold it is thick, and as it warms up, it will thin out and problems caused by out of tolerance (worn) parts will show itself. Ours wasn't pumping correctly(running lean, no loading), so we had it rebuilt and the guy found the main lobes were worn.

Regards,

Rich Cizik
MoW Foreman
Ct Eastern RR Museum
Willimantic, Ct 06226
http://www.cteastrrmuseum.org

From the pictures I can see that the filters are lower than the fuel tank, after the machine shuts down the filters are almost dry, then there has to be a restriction between the fuel tank and the filters. You also said when you dump the fuel out of the filters filters no water or crud which is a good sign.
I agree with DR on replacing the fuel lines to the filters. Also next time you change the fuel filters, cut the top off'em with a hacksaw and take a look at the paper element in side for any type of grit, crud, algae, ect.
Also the tank may have been cleaned out but don't forget about the tank or fuel cans you use to fuel the machine. I had to drain many fuel tanks on welding machines because of some of the stuff that came out of fuel cans on job sites and that were laying around the yard collecting water and other unidentifiable concoctions.