NEED HELP with farmall 400

[gregdoerfler]

i have a farmall 400 diesel and went to change the oil for the summer after sitting all winter and it had about 3 gallons of diesel fuel in the oil,it seems that it is filling up the pump and leaking out to the motor (the pump has its own oil supply so it should still not go into the motor) please give any help on what to look for inside or somewhere to look.

 

[Morphious]

could you have an injector not closing all the way? Those tractors are gravity fed diesel, and if the pumps loose enough with a leaky injector? Just hypotosizing here. I had a farmall 340 so I'm a little familiar with them.



Morph.

 

[bmoeller]

Sounds almost like a seal went out to me, unless you had some kids around and they decided to have some fun . I'm not all that familiar with these diesel engines (Boss does have a gas 460 though. Had to fix the hydraulics on it today. ). Is the pump lubed the same as the P7100, or is it completely independant from the rest the engine lube? Been too long so I don't remember for sure.



EDIT- Just saw Morphs post, that's a thought too.

 

[J DeMaio]

I don't know a whole lot about these tractors but know that they are a challenge and expensive to restore. I believe that the 300,350,400,450 farmall diesels were all of the start on gas, run on diesel. I think they had like 3 valves per cylinder and a spark ignited gasoline fuel system then a valve to switch over to the diesel system, as well as that fuel system. I'm pretty sure this is the case. Anyway, the first place that I would check would be the transfer pump, does it have one? If not then I'd get the injectors tested and the injection pump. It may be expensive and hard to find someone to work on this old system. Best of luck.



John

 

[gregdoerfler]

the pump is completely lubed independently and i don't think it is an injector because when i open the pitcock for the oil level in the pump it is full of diesel. i think there must be a leak to get fuel to leak into there and another is leaking between the pump and motor.

yes it does start on gas the changes to diesel. it did this just sitting not running. it may have been doing this for a while now but i always turn the fuel off after i shut it off but for some reason must have forgotten to shut it off for winter.

 

[illflem]

wish they were all this easy

The fuel transfer pump is leaking internally, replace it.

 

[gregdoerfler]

well just so happens that i have one laying around from changing the injector pump a couple years ago (good thing for me, i just cant seem to throw anything away). put it on tonight will see tomorrow if it leaks. but any idea why it could have been going into the block also?

 

[illflem]

Diesel floats on top of engine oil, three gallons is a heck of a lot of overfill, probably raised the level up to the cylinders where it seeped past the rings over time. In fact with the fuel leaking freely into the oil sump it would eventually fill the entire engine with fuel up to the level of the fuel in the tank over time unless it first starts overflowing from a breather or the dipstick tube. I wouldn't doubt you'll find the oil filter has diesel in it. Probably did it verrrry slowly, if the tractor was running more often you might not even notice the leak.

Besides changing the oil right away I'd recommend changing it again after a short period of operation to flush all the diesel out.

 

[tractorman]

Try the Farmall tractor discussion board at www.ytmag.com. They should be able to help you out.



http://www.ytmag.com/farmall/wwwboard1.html

 

[dzlpwr]

There is a couple front seals on the drive shaft of the injection pump. If it wears into the bushing of the pump too far, or a seal gets cut, it will leak fuel into the crankcase. If it has been sitting for a while the seals will harden and crack also. It will fill the crankcase pretty rapidly b/c the fuel pressure inside the pump is about 80 psi or so. I would send your pump in to have new seals installed and recalibrated.

 

[Blakers]

If it were me - and the tractor runs good besides this little problem - I would just shut the fuel off when parking it. I have a Super M with gas engine and I shut the fuel off in case the carburetor float valve seaps.



The 400 diesel and the Super MD (same engine) have a tendency to crack heads if shut down hot. Always let them cool down good after working them.



Take care.