# Ih 684



## alourinho (Feb 28, 2016)

Hi,


I recently purchased an IH 684 - i already started it once or twice but then i ended up being unable to do so - so, i did the following (note that im quite the rookie...):

1) At first i thought that it would not be possible to have ran out of fuel as the fuel gauge is showing that the tank is full - as such, i though hey, i have to change filters as i should already have done immediately after bought the tractor

2) I changed the filters - big mess, i forgot an o´ring and i end up over tightening the primary filter glass bowl - it was leaking nevertheless - at this point i already noticed that i was really out of fuel (the gauge is broken after all) and i tried to start the tractor with no fuel - i still heard it starting but then it died

3) The next day i noticed that the glass fuel bowl had blown during the night - should not have overtightened it

4) I bought a new glass fuel bowl in an IH dealer - expensive - as soon as i received it, changed the o'rings again, fitted the new glass bowl and everything looks nice - no leaks it seems

5) Tried to start it at this point but no go - at this point i remembered that when all this thing started i tried to start the tractor with no fuel! well, i will have to bleed the whole thing now - so i did:

6) I checked that the fuel tank valves are all open

7) Opened the venting screw on the fuel primary filter until a continuous flow came out

8) Opened the venting screw on the secondary primary filter until a continuous flow came out 

9) Unscrewed the fuel line inlet on the injection pump AND nothing came out - at this point i put more fuel in the tank - this did the trick as fuel started to come out of the injection pump inlet - now i knew fuel was reaching the injection pump

10) Unscrewed (1 to 2 turns) the outlet of one of the injector lines

11) Tried to start it - no fuel came out of the injector line and the tractor didn't start 


And now for the 1 million dollar question - does anyone have any idea of what can it be - besides being a problem in the injection pump, in which case i will just roll over and die given the price for a new pump (1000$+).


Thanks in advance for your help.


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## sixbales (May 18, 2011)

Howdy alourinho,

Welcome to the tractor forum.

One thing I have learned is to never run out of fuel, because my tractor is a PITA to get re-started. You will learn the same.

Few things to check:
1. If your tractor has a kill rod to shut-off the tractor, it shuts off the fuel to the injection pump, so make sure it is "in". If it is shut-off with the key, it actuates a fuel shut-off solenoid, so make sure the key is on.

2. Set the throttle half way or more to enable the pump to move more fluid. 

3. Your tractor may not be gravity flow to the injection pump, you may have a fuel pump in the system. Check it.

4. Make sure you have plenty of fuel in the tank, and start the bleed process over again. 

5. Below is a diesel purging procedure for a Ford tractor. Review it to make certain that you haven't overlooked something.
___________________________________________________________

This is a procedure originally posted by Jerry/MT on the YT Forum. I’ve added a few things, but it’s the best detailed bleeding procedure that I’ve seen.

My tractor can be a PITA to get started if I run it out of fuel, or if the filter gets plugged. 

How long has it been since your fuel filter was changed?? Might be a good time to change it.
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Start at the fuel outlet of the tank (inlet to the filter). Shut the tank valve, remove the line at the filter inlet and holding a suitable container to catch the diesel fuel, open the valve. You should have a CONTINUOUS rush/flow of fuel out of the line. If it dribbles or is intermittent, check the fuel cap for a blockage of the fuel vent or the strainer upstream of the valve for clogging. The strainer/screen is attached to the shut-off valve, and is positioned up inside the tank. You will have to drain the tank and pull the valve to clean the screen. 

If you have good fuel flow at that point, reconnect the line and open the bleeder screw at the top of the filter. Turn on the tank valve and wait till you have a steady flow of fuel with no bubbles at the top of the filter, then close the bleeder screw. 

Your pump may have a bleeder screw. If so, open that until fuel streams out with no bubbles, then close it. Otherwise loosen the inlet connection at the pump and purge air at that point. 

Go back and make sure ALL the fittings in the fuel delivery system are tight so they cannot suck air.

Make sure the battery is fully charged. Loosen the fuel fittings at the injectors, either one at a time or all at once. Crank the engine till you see all fuel at the injector fittings and then tighten the fittings. If you do individual fittings, the engine will usually start before you get to the last fitting. 

Alternatively, you can "tow-start" it to save wear and tear on your starter. Leave the injector lines cracked open at the injectors at first to purge the lines. Then tighten them up and she should start.

Your injection pump puts out a very small amount of fuel (high pressure/low volume). BE PATIENT. If the lines are totally empty, it takes a lot of cranking to fill them up.


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## RC Wells (Dec 26, 2008)

Depending on the injection pump on your tractor, IH 684 used three different types, it may be necessary to first assure you have a full fuel flow to the injection pump, if so, then you may need to crack an injector line just enough to allow the air to bleed. Cracking the line is a two person job, one to crank the engine while the line is cracked open, and one to crack the line and then close it as soon as the fuel begins to come out under pressure.

Be very careful, as the pressure on the injection line is high enough to inject diesel right through the skin and result in serious damage, including death.

The simplest process is to purchase an electric diesel compatible fuel pump and install it in the line from the tank to the injection pump, turn it on and let the fuel from the electric pump evacuate the air out of the injection pump via the overflow line, then try starting the tractor with the electric pump still running. It almost always will start within seconds once the air lock in the injection pump has been eliminated. They generally will start up on one, then two, and finally all the cylinders as the air clears the injectors.

I would install the electric pump myself, just to be safe.


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## alourinho (Feb 28, 2016)

Hi,


Thanks a lot for your feedback - just to be sure - i tried to crank it twice for 30 seconds - is it usual for it to start with just 2 tries or will i need much more patience?

It makes sense that the injector lines are high pressure low volume as after cranking the outlet of the injection pump seems dry.


Thanks in advance.


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## alourinho (Feb 28, 2016)

Hi,


Thanks a lot for the quick answer.

About the fuel pump, should the fuel pump be installed between the injection pump and the fuel tank, in the overflow line which carries fuel from the injection pump back to the tank?

I also unscrewed a bit the injector pump overflow line screw to let air out but there was no fuel coming out.


Thanks in advance.


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## Fedup (Feb 25, 2014)

Fuel pump should be installed between the tank supply outlet and the fuel filter base. Thus it supplies fuel under pressure through the filters then to the injection pump.


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## alourinho (Feb 28, 2016)

Do you have any idea of how the pump would be powered on an IH 684?


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## RC Wells (Dec 26, 2008)

Your tractor has a 12 volt DC electrical system, tap into that with a 12 volt electric fuel pump.


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## alourinho (Feb 28, 2016)

Hi,


Thanks a lot for all the help - I finally managed to bleed the whole thing and start it.

Nevertheless while unscrewing one of the injector pump outlet pipes I used to much force and ended up cracking the joint between the pump and the outlet pipe (before the nut). As such the pump is now leaking abundantly when the tractor is running. To solve the problem I was thinking of welding the joint. Nevertheless I'm not sure that during the process will ignite the diesel due to the welding heat - is it safe to do this?


Thanks in advance.


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## RC Wells (Dec 26, 2008)

Never weld any part of the fuel injection system, replace the broken part. 

While the pressures do not appear that great right now, they are in the 18,000-22,000 PSI range, and a weld will be too brittle to safely hold that level of stress. The crack will reopen, the fuel will atomize as it sprays out, and it then becomes very explosive - think barometric explosion that can be devastating.

If you can locate a farm tractor salvage yard in your area, they usually have a good supply of rebuilt pumps at affordable prices. Just about any diesel fuel injection pump repair facility will have, or can easily obtain, the components necessary to repair the pump.

If the plate on the pump itself is cracked, do not attempt to disassemble it yourself. The smallest amount of dust can permanently damage the pump. If it is one of the removable outlet fittings, locate a new one, then remove the old fitting and replace it so that no dirt is near or able to infiltrate the process.


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## alourinho (Feb 28, 2016)

Hi,


Thanks for the answer.

I will not weld it - nevertheless the outlet fitting which is broken seems to be part of the pump main body - it is not screwed in it - as such I believe I will have to replace the whole pump...

I found in an auto store a product named cold weld paste which becomes quite hard as it dries after application. Could this be an alternative to replacing the whole pump or do you advise against it?

Thanks in advance.


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## alourinho (Feb 28, 2016)

Hi,


After all the outlet was just unscrewed - no need to change pump - its all alright now.


Thank you all for all your help.


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## duanedawn18 (11 mo ago)

I have a IH 684 2wd with a loader and my Buddy has a IH 584 FWA and a question i have is can i take the FWA off the 584 and put it on the 684? the tractor looks identical but would love to make mine a FWA


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## LouNY (Dec 15, 2016)

It would depend on the final gearing on the 684 and the 584 and the tire sizing.


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## duanenyyboy (11 mo ago)

LouNY said:


> It would depend on the final gearing on the 684 and the 584 and the tire sizing.


Thankyou.. how can I tell if that is the same?


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## LouNY (Dec 15, 2016)

I don't know on the 84 series on the 74 series the factory service had the full breakdown of the serial numbers to the optional and standard equipment.
I would expect that you would have to swap quite a bit including the transmission as the 4wd output comes out of the rear of the transmission.
The best bet would likely be to go online to the IH parts breakdowns for both tractors and search all the related part numbers.


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## duanenyyboy (11 mo ago)

LouNY said:


> I don't know on the 84 series on the 74 series the factory service had the full breakdown of the serial numbers to the optional and standard equipment.
> I would expect that you would have to swap quite a bit including the transmission as the 4wd output comes out of the rear of the transmission.
> The best bet would likely be to go online to the IH parts breakdowns for both tractors and search all the related part numbers.


These series have a bolt on 4wd transfer case on the side of the transmission with the engaging switch in the transfer case .. I’m just not willing to do the swap if I don’t know it’ll work but I’ll see what I can find online once and go from there .. Thanks for your help


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