Case 900 tractor

[jrobison]

I am having difficulty with a recent barn find. It is a 900 Case that hasnt been run for about 20 years. I got it started but the throttle doesnt alter the engine speed and it seems to only run at full throttle. To shut it off I have to turn off the fuel and choke off the intake. I suspect the rack is stuck or frozen, what kind of job is that to repair, or would it be something else? The tractor was running when it was parked in the barn and the farmer I got it from always kept it shedded.

 

[tomturkey]

sounds like a job for dieseltech, a frequent poster on this site. knows his way around a Case diesel pump. I have learned a bit from hanging around here, a long term non running diesel tractor requires special care to bring it back in to service. Good luck to you. A good save for the CASE tractor cause. gobble

 

[donjr]

Don't really know the 900, but my 800 had a link broken off in the steering column. It sat for 15-20 years in a fencerow, too....

 

[pcrh]

Hi:

My understanding is if the rack was frozen or stuck it would not run as you are only applying fuel to one cylinder. A stuck linkage on the other hand would do as you describe. Might be a place to start.

 

[Roger S]

I would need to see the other side of the tractor to see the pump design, but if it's original it should have the PSB rotary pump on it. The fuel lines are in a circle on top of the pump. If it has that pump there is a cover held on with 2 bolts just below the fuel lines on the body of the pump. Take the cover off and you will see the metering valve with a rod that disappears to the rear of the pump. See if it is stuck, should move forward and rearward. If it is stuck spray with wd40 and gently try and free up with needle nose pliers.

 

[muleman51]

I thought they had bosch inline pumps.

 

[rustred]

lucky u got it running! those american bosh pumps like to stick, then when engine is turned over it breaks the shaft and ur done. parts pretty much obsolete. get diesel tech on it. the inline german bosh is a better pump that the 930's had.

 

[jon f mn]

Of it still has the rotary pump it is likely the throttle shaft is stuck, a common issue when they sit. You are lucky the head wasn't stuck and the drive got broke. The throttle shaft is under the cover just below the head where the lines bolt on. Take the cover off and the shaft is under it. Sometimes you can work them loose, other times you have to pull them out. Do not polish the shaft with anything abrasive, just clean it. Be careful when pulling the shaft as there is a tiny spring I'm there that can easily get lost.

 

[Roger Link]

If the radiator cap is above the hood it's probably a 900-B, they should have the inline fuel pump, most likely the rack is sticking, on the front end of the pump is a round cap with 2 flats on it, that can be screwed off to see the rack, sometimes some penetrating oil and lightly pushing or pulling on it will free it up. Always keep your favorite board handy to choke off the air cleaner.

 

[jrobison]

This one has the German pump, external drive.

 

[jrobison]

It does

 

[used red MN]

Mule man, according to the parts manual tractors with serial number 8141036 and later have the inline Bosch pump. Prior to that the pump is described as a ..single plunger.. Which I assume means that plunger develops the pressurized fuel delivery and a rotary distributor valve delivers it timed to the correct cylinder. Thus a rotary pump as Jon said above or below depending on the view you use. See attached Engine section, subsection 016 and 017.
CNHI Case 900 parts diagrams

 

[jrobison]

This tractor has a German Bosch inline pump with external drive. The linkage is fully functional however the shaft attached to the pump is under spring tension and when I disconnect the throttle link it goes to wide open and shows no change in engine speed when I pull against the tension. I also suspect it might be a governor issue.

 

[jrobison]

That sounds doable and if it works I can still make it to the threshing bee in Sterling, I will give it a try thanks.

 

[rustred]

900 B IS THE PSB PUMP.

 

[rustred]

Picture Please, as that will tell the story. not following ur external drive.

 

[Traditional Farmer]

Had a similar problem with an Fiat/Oliver 1465,took the back cover off the pump nut had worked off the throttle shaft.

 

[RJKeith]

Not sure about the 900, but I have an 800 that sometimes doesn't want to shut down. Over time, the throttle spring has weakened, so unless the linkage is clean and lubricated the spring isn't strong enough to shut off the fuel. So that is something else to check.

 

[Roger Link]

Many of those early model inline pumps had there own oil in the pump, most times it never got changed or watered down with diesel fuel so that the governor didn't get oiled properly or no oil at all, best is to time it, take it off and send it to a repair shop. If its in real bad shape a pump from a 930 or 1030 will bolt on, just change the fuel setting so it doesn't smoke to much.

 

[mEl]

That is the earlier pump, there is the fill opening that looks like a breather on top, there is a drain plug on the bottom with a drip tube that has a holder on a pan bolt, it takes the same oil as used in the engine, if the rack is stuck all cylinders will be in the same fuel delivery setting as they all work off the common rack. You could take the nut off the front of the pump that has the two 3/4 flats that covers the end of the rack. Very gently try to move the rack back and forth, do not force it as there are very fragile gears and parts in there. As others have suggested if the simple stuff does not work, Line up the timing marks in the hole underneath the 1 1/4 plug ahead of the pump, take it off and send it to Dieseltech, he is a very good source of knowledge and freely gives his time helping us sort out our own problems and deserves our support.