Okay guys I need help on a reoccurring issue I'm having... 1988 international s1900 with a DT466 Dump truck I recently purchased this truck and it broke down on the way home. I know the previous owner and he's a trustworthy guy and he says he did not have this issue prior. Breakdown #1 15 Mile road Trip. Broke down at Mile 13. Crank no start, no fuel. Tank full Dragged it home, drained all the fuel out of it put fresh fuel in and changed the fuel filters which were nasty. Bled it all out. Started right up. Breakdown #2 Thought it was all good to go. Headed to the fuel station to fill her up.... Made it 3 miles. Same crank no start. No fuel. Dragged it back home. Checked the fuel filters. They had no diesel in them. Suspected a clogged supply line. Blew backwards through the supply line. No restriction. Then I clamped off the vent hose to the fuel tank and pressurize the fuel tank with shop air. Fuel pushed through the supply line no problem. I filled the fuel filters with this procedure. Re bled the system. Started right up. Breakdown #3 This time I was cautious and only drove the truck around the farm. Sure enough it broke down again and this time I went directly to the fuel filters. When I spun the first fuel filter off there was a vacuum on the filter. as soon as the o-ring cracked open you could hear a rush of air being pulled in. Of course the filters were empty. I needed to use the truck to move some stuff on the farm so I just pressurize the fuel tank again to push fuel into the filters and rebled the system. Started right up. Anybody have any ideas where to look next? I'm thinking maybe a restriction in the filter housing itself????
Were the tanks on a vacuum too? Did you verify vent line was clear?
Did you look in the tank when you drained it? I found a piece of clear plastic bag in a tank once that was absolute hell trying to diagnose. It would get sucked over the inlet, kill the engine, then float off for awhile, returning randomly!
No vacuum on the tank Return line- untested Yes I looked in the tank after drain. looked good for an old tank. nothing floating around that I saw plastic bag issue would be a hard one!
Is the supply line collapsing? Have seen that if the hose gets soft it can collapse and once engine dies and the suction is off it returns to normal. There could be a flap in the hose that works the same Is there some kind of suction screen on the pick up. I would have a really good hard look to see if there is something inside, have pulled some interesting things out of fuel tanks in the past. Any rust in the bottom of the tank, have had that plug pickup lines too, meaning flakes of rust.
Sounds like supply line in the tank to me. I have seen them crack and suck air intermittently. Ive seen them plugged at the screened end in the bottom of the tank with black tar looking stuff. Iv seem them break off completely. All you can do is start in the tank and work your way to the engine. Or maybe just for a test I would take a 1 gallon jug and temporally use that as your tank, drive around the farm for a while and see what happens?
One problem with a collapsing fuel line on a International of those years, International started using black nylon air brake tubing back in 1978. IIRC and the last bunch of IH's I worked on which included years from 78 through 91 all of them had nylon fuel lines. Pretty hard to collapse those unless they were kinked or near a heat source. And I suppose the nylon could crack but I find it unlikely. Using everyone's favorite {Just saying}.
Chased floaters in a tank for close to a Day, always out of sight where could not "See" them until driving then would block the line until dropped a filter or sat long enough then would restart. First off, PULL The Tank, remove the sending unit or blank cover and visual the ENTIRE Bottom of the tank. I am guessing this has the standard rectangular black steels on it? Then remove the Standpipe if equipped and look as well remove and clean the vent now that is accessible, Finally VISUAL inspect every section of fuel line up to filter head Suction Side.
Ok. You guys talked me into doing what I was trying to avoid but knew was the right move... drop the tank and disassemble it Yes this has a nylon fuel line. I like the run it off a jug test too. I will do this while the tank is out if I don't find an obvious plug
Look for check valves in the filter housing, hidden prestainers, and even look in the fittings where they are restricted just go though the fuel system with a fine tooth comb and you will find it
Different engine, different fuel system, but read through this thread and see if you get any ideas. HeavyEquipmentForums
i encountered an international of the same approximate vintage having some similar symptoms ( with the exception of the vacuum at the filter) and i determined there was an issue with the standpipe in the tank. owner wanted a fast cheap fix so i took the plug out of the lower front of the tank and plumbed the fuel line into that. i told him to not let the fuel level to get below 1/4 or the fuel could slosh to the rear and pick up air. saw him weeks later and it was still running good. if i recall correctly, in order to pull the standpipe i think i would have had to loosen the tank and move it to get clearance
Pulling tank is simplest and cleanest
Drove a Mack truck. 350 Mack, Brand new. about a week in, it would starve for fuel. First time it went on the hook. Mack tried it in the morning, no issues. They changed filters and sent it back. 2 days later same issue. This time it in the middle of the week so they sent a guy out. He pulled the fuel line off and blew air through it. There was paper in it. Tag from the factory off the inside of the fuel cap. supposed to be removed during assembly. two months later same thing. Our mechanic checked the line, nothing. Tried priming the filter with the hand pump, two pumps and it jammed. pulled it apart and there was the rest of the tag. 25 years years later, still no issues
If your filters are losing prime you will either have a blockage or you are sucking in air somewhere. It sounds like you have eliminated a blockage so that leaves sucking in air. Whichever filter that is losing prime the air leak will be in the line before the filter that loses prime. I would carefully check your lines and every place they make a connection. It is possible to have a leak in the suction side of the fuel system and not have fuel leaking.
And check all around the fitting for cracks in the housings... etc... I have seen cracked housings let air in and not fuel out... or rig some fittings up that you could put a low pressure on the whole filter system and let it sit for a while and check for leaks... do it with fuel or do it dry and have a spray bottle of bubbly water there to test with.
Definitely sounds like something is blocked. You can tee into the suction line and run a hose to the cab with a vacuum/pressure gauge, and it will show you what vacuum is being pulled on the system. Put the tee halfway between the tank and the first pump, then you'll know which way to move it or look for the obstruction. Really, it will be easier to take apart the whole system and clean it, then you only have to prime it once.
There aren't that many fittings/lines to remove and clean. A couple hours and that side of the problem could pretty much be eliminated for the life of the truck. Only works if you drop and clean the tank too though. And as a bonus, you'll get up close and personal with each piece and be able to see if anything is cracked.
Exact same thing happened to me with an 86 Pete I owned. Drained the tanks, and found a the clear plastic from what looked like a cigarette pack.
Thanks guys all this virus chaos has slowed me down on this project but I hope to get to it tomorrow or Monday. Ill let you know what I find
One of the mines I work at has a CAT 980G with this problem; it's got a pinhole letting air in, so needs to be primed at the beginning of the day and whenever the machine is shut down for more than around five minutes. The dealership mechanics can't find the leak, so they just deal with it.
Sorry everyone.. I'm alittle late to this party.. As u probably know, when u pulled the filter down & heard a rush of air, its vacuum.. the supply pump on the engine/inj. pump IS PULLING fuel.. but none available which means either the LONG RUBBER HOSE is collapsed or theres a rag in the tank.. I wish I had a nickle for every hose I replaced on a TD466.. I have a tail lite bulb that i rigged up on a stick w 2 long leads that i clip on the truck batteries.. to look into fuel tanks.. works like a dream.. Most of the DT's I've worked on have a hidden water separator up behind the passenger side wheel well..
On my old 1974 International 8V71 Detroit on my slasher truck I had similar issues, Turned out the fuel hose from the tank to the fuel pump was flattened out where it laid over the frame, Just closed up from it own weight laying on the frame. New hose and ran like new again.
Like PumpguySC said, this inlet filter screen often gets overlooked.
UPDATE: solved! It was a fuel treatment cap (the little penny sized ones that pop off, not the screw ones) someone must have dropped in the tank at some point. It was getting sucked up and blocking the fuel flow. Truck is back to running well! Thanks for the help guys
Kudos for posting the update, but I wonder if it was really necessary to start two threads regarding the same issue..?