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Ford 7740

11K views 31 replies 5 participants last post by  StevenA 
#1 ·
Should you be able to feel suction when pushing the plunger on fuel filter head with the spin on filter removed.I'm trying to figure out if the plunger is working.
 
#2 ·
Doubtful. I suspect you might feel some suction if you leave the element in place, remove the line coming from the water separator where it threads onto the primer pump/filter base then work the primer. The fitting is small enough you can cover it with one fingertip and probably feel suction pulses.

What makes you concerned about the suction or lack thereof?
 
#4 ·
So what prompted the discussion to begin with? You changed the fuel filter and can't get the engine started? It ran out of fuel and you can't bleed it out? Engine runs but acts like it's starving for fuel? You can test for suction as I stated earlier, but what's the problem?
 
#6 ·
Then you have any number of possibles. So you don't know how/if it ran before all that took place, why it didn't run, what all was "messed with", or pretty much anything about the fuel system in general? Do you have any experience with Ford 40 series systems to start with, or are you basically working your way through?

I'm assuming it has an auxiliary fuel tank under the cab? If so, any idea where the fuel level is in either tank? If it's only got fuel in the lower tank, and it's only partly filled, then you will no doubt have trouble getting it bled, whether the hand primer works or not.

If that's the case, I have a few suggestions for you should you be interested.
 
#7 ·
Then you have any number of possibles. So you don't know how/if it ran before all that took place, why it didn't run, what all was "messed with", or pretty much anything about the fuel system in general? Do you have any experience with Ford 40 series systems to start with, or are you basically working your way through?

I'm assuming it has an auxiliary fuel tank under the cab? If so, any idea where the fuel level is in either tank? If it's only got fuel in the lower tank, and it's only partly filled, then you will no doubt have trouble getting it bled, whether the hand primer works or not.

If that's the case, I have a few suggestions for you should you be interested.
I have no experience with the 40 series, it has 1 fuel tank out in front of the radiator I emptied out the fuel tank and flushed with clean fuel put 5 gallons of clean fuel back in tank, now trying to bleed fuel filter.
 
#8 ·
Okay, now we have something to work with. Only one tank helps a bit, but when starting from scratch as you are, five gallons is still pretty low. When you emptied the tank did find and use an actual drain (there is one, by the way) or did you use some other method? That's probably not too important just yet unless you found water in the tank. Depending on what was (as previously mentioned) "messed with," where you go next is still a question, but I would start at the water separator. That's one of the biggest issues with this system if you don't know how to deal with it. If it were me, I would probably bypass it for now until you get it running and see what else you have to deal with. The water separator has two parts and three gaskets, the same gaskets as a CAV fuel filter, and most of the time the gaskets are seldom replaced so they could be really old and prone to leak air into the system, which can make priming the pump with a low fuel level difficult to impossible. If you're confident on the tank condition/serviceability I would put more fuel in, which will make this much easier. You'll need it sooner or later anyway.

Personally, if it were my tractor I would add an electric fuel pump between the tank and the water separator. That puts fuel through the separator under pressure not vacuum. Fuel leaks are much easier to see than air leaks. Pretty much eliminates the need for the hand primer as well. I've done that to any number of forty series tractors with no ill effects. Particularly those with two tanks. It solves a lot of problems.

Once you have fuel to and through the filter, to the injection pump, make sure you have 12 volts to the shut off coil while cranking, as well as with the key "on". There's nothing on the pump to bleed, just crack two or three of the easiest to reach injector lines at the injectors. With the muffler and other obstructions, some can be difficult to access. Sometimes you can get by without bleeding at the injectors with that pump, but in this case probably not, given your circumstances and it's history. Having the batteries charged while doing all this will help too.
 
#30 ·
Personally, if it were my tractor I would add an electric fuel pump between the tank and the water separator. That puts fuel through the separator under pressure not vacuum. Fuel leaks are much easier to see than air leaks. Pretty much eliminates the need for the hand primer as well. I've done that to any number of forty series tractors with no ill effects. Particularly those with two tanks. It solves a lot of problems.
Hi,

I have been thinking about doing this (adding an electric pump) as it is very hard to prime mine (6640) with only fuel in the aux tank. some questions:

Is there a pump that you would recommend, and where do you fit it (engine bay or at aux tank)?
Do you use it just for priming, or do you run it from the ignition all of the time?
If from the ignition, do you route via the oil pressure switch so that it only runs with engine turning over?

Appreciate your help.
 
#9 ·
Ok thanks that will help, the tweaker that messed with the tractor also took parts off the separator, so I by passed it, I also plumbed an old lift pump off my dodge cummins just to prime the fuel system but have not tried to fire it yet.I got my 2nd covid shot today and didn't know how I would feel so probably going to try and fire her up tomorrow.I did drain the fuel tank which had water and sludge in the bottom.I went to harbor freight tools and bought a cheap suction gun and pulled fresh fuel through the line from the tank and flushed that line also
 
#10 ·
Well be aware there is a drain valve on the tank, and it's below the level of the outlet fitting. If you haven't had that open yet or actually removed the tank to empty it, you still have a quantity of water and whatever else still in there. It can slosh across at some point on a side hill when the right side is higher than the left.
 
#11 ·
Ok I pulled the plug on the side the fuel line connects to and drained that side of tank then opened petcock on other side of tank and was surprised that fuel came out, they look to be the same elevation on the tank but the drain side is lower, so I let it drain completely
 
#13 ·
I tried to fire the tractor today I pumped the fuel system up with the cummins manual lift pump it worked good only problem was fuel spewed out the top of the filter plunger so I quit for today.I can order a new fuel filter head from all states ag for about 50.00 what do you think of the quality of that item.I got a quote from meyers ward for 145.00 I just dont want to sink a bunch of money in her till I know the engine is good. Any thoughts?
 
#14 ·
Since we're into bypassing anyway, why not just bypass the filter base as well. You have to remove the lines from it anyway if you change it, so why not pull them off now. Get a $5 inline filter and a few inches of hose, put that together and try again. Much faster and cheaper than deciding on a new base assembly. You don't need much filtering capacity just to run it long enough to evaluate the motor condition and the other tractor functions.
 
#16 ·
Ok so I bought an inline filter and bypassed the plunger filter rolled it over had fuel coming out at the injector connections.Battery isn't super strong so hooked up my dodge cummins with 2 batteries and rolled it over no start.noticed while I was rolling over fuel leaking somewhere around the fitting block connected to the underside of the injection pump.wonder whats the next move.
 
#18 ·
It’s probably the starter that’s bad.. just going by experience..
The fuel leaking around the bottom is more than likely coming from somewhere else and dripping off the bottom, again just going by experience.
U could clean the pump w Brake Kleen, dry it off w air and sprinkle baby powder on the top side..
THAT will show u where the leak path is.
Good luck
 
#20 ·
Update so I pulled the starter and noticed flywheel was rusty, sent starter to a starter guy.He calls back and says nothing wrong with the starter.I didn't mention to you guys that the clutch pedal won't move, the shaft its connected to won't either. So today I pushed a small srewdriver in a plugged with mud hole under the tractor and rusty water started draining out.I wonder if the clutch is froze and that causes the starter to pull harder. I'm picking up the starter tomorrow, what do you guys think should be my next move.
 
#21 ·
I guess a starting point would be how MUCH rusty water came out of the clutch housing? That's a rather large cavity so it would take a couple gallons at least to get much of the clutch wet enough to cause things to seize that tight. Maybe I missed it in the earlier posts, but is this a cab or platform tractor? Cab tractors have a hydraulic release mechanism for the clutch, platform tractors have mechanical rods and linkage. The two would be totally different to diagnose problems in that area. Also I'm assuming this is a 12 X 12 mechanical shuttle transmission, yes/no?

As for why it's so hard to turn over. Could be one or more of a number of things. Batteries, cables, connections, all that of course. Starter is still suspect in my opinion, depending on how your starter man came to his conclusion. Was it dismantled and inspected, or just "bench tested" and "seems to operate correctly"? A number of shafts and gears need to turn along with the engine while cranking, even more if the clutch won't release. As do the hydraulic pumps, so that's a fair amount of resistance as well. With the starter off you can try turning the flywheel with a bar for a bit and get a feel for how hard it turns. That might tell you something.

With the clutch not working I would advise against trying to pull start it. While that might be effective, it probably won't end well.
 
#22 ·
I would say about 1 gal of water came out of the clutch housing, I did notice some water pushed out when I greased the shaft that goes into the clutch housing it has zerks on both sides of tractor.This is a platform tractor its a 7740S, tractor data says it has a 8 speed economy. Starter guy said he tore it down and said it looked new inside he said theirs nothing wrong with it.I will go out and turn flywheel with bar and report back.thank you for all your help.
 
#23 ·
Probably the wrong place but I see activity here, I need help determining the year of a Ford 6610, the serial number doesn’t look like anything I am seeing online. Attached are numbers stamped on block and trans unfortunately there is no ID plate. Can anyone help me out?
 

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#24 ·
Update on the 7740, I got the starter back from the starter guy, cleaned the ground connection, installed the starter hooked up 2 batteries together rolled her over, shot some starting fluid in and she fired up. It started and was running at really high rpms so I shut it down and adjusted the idle lower, fired it up again and it ran really nice.I noticed while it was running it was leaking a lot of filthy rusty diesel fuel out of the injector pump got a small mirror and seen it leaking from under the top cover, let it run until it finally started leaking clean fuel and then shut it down.The leak is quite large almost like there is no gasket.I need to order a gasket and stop the leak.Now that I know I have a good engine I will be spliting the tractor to fix the clutch, the dairy across the road has a gantry crane I can use.I have never split a tractor before that should be interesting.
 
#26 ·
Ford 7740 update, I ordered a kit for the fuel pump top cover, went to install cover gasket and it was the wrong one.The one I needed has 4 holes in it at the corners where the bolts go through.I looked online for 1 but most came from the UK or Germany.I went to the loacl tractor dealer and ordered 1 gasket for $17.00 that is located in Reno NV supposed to be here Wednesday so I will let you know how that goes.
 
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