2020 C model Injection Pump

It seems I have the same problem that "1 Dollar" posted under this subject a few years ago. My 2020 (TYP T5R3C / SER 075265T) is getting diesel in the crankcase, even when parked. I've already changed the transfer pump with no help, so the injector pump is now the suspect. It's the "bad news" model CBC431-3AL pump. Since this tractor has blown what I think is fuel-smoke (no significant oil loss) for the few years I've had it, the injector pump is probably suspect for that as well. Would anyone have any current leads on the preferred models that "jdemaris" listed (DBGFC431-25AJ, JDB431AL2408, or JDB431AL2731)? Also, I understand that installing the pump requires setting the flywheel to the appropriate top-dead-center position with the set pin. Does anyone know the trick to turn the flywheel manually to get that proper position for the changeout?

While the "C" pump can be resealed, might be best in the long run to find another pump with the lines from a salvage yard. I thought that engine had an opening near the flywheel like other JD engines used for crankshaft rotation service.

You are doing the right thing by changing it. Neighbor had a 2520 with the little pump that always seemed to smoke. Dad changed it over and it ran better and the white smoke went away. You will also need a complete set of fuel lines.There are many pumps that will work you can even use the newer ones with an electric fuel shut off by just running an extra wire from your key switch.As far as turning it over Deere had a special tool to stick in and use but you can remove the starter and stick a bar in,put a pipe wrench on the shaft between the crankshaft and hyd. pump or if you do not have independent pto enguage the pto and put a pipe wrench on that. There is a special tool that helps with installing the injection pump, it clamps the seal so it can not roll. If the seal does roll you will get fuel in the oil. I am not sure but you might have to change the gear behind the timing cover as well. I do have a shop that will rebuild your pump if interested. He did one last year on a 4020. I would also advise you to find a John Deere service manual as they give good direction on pump removal,instulation and timing. Good luck. Tom

Dieseltech,I just posted an injection pump question on tractor talk. Could you take a look at it and give me some ideas? Tom

You might need to switch drive gears. There was a
shaft for switching to a DB pump but it would be hard
to find one.

Deere sold special conversion shafts for what you need and like the other poster stated - pretty rare find. My Deere 300B appears to have come with one right from the factory. I suppose Deere had a bunch of engines already setup up for the CBC pumps, could not get them anymore, so converted at the factory. I just rebuilt my pump and luckily no broken shaft. If it ever does break, I will have to get a new timing gear and new style shaft which is likely what you have to do. But my memory is not perfect. Early C pumps connected to the timing gear with three hollow shear-bolts. Later C-pumps did not use those shear-bolts and relied on a designed weak-spot in the driveshaft to break if there was a pump turning too hard. So the later timing gears might accept a DB and JDB style shaft. Keep an eye on Ebay. Those pumps turn up.

I am surprised the rack & pinion throttle gears are still good in your's. I have flipped a lot of them over to get more life out of the one gear.

I suspect any DB431 pump can be made to work, if it comes off a Dubuque engine. Look for pumps from - 400, 410, 440 log skidder, 480 forklift, 450 crawler, 510, 530 combine, 165 combine, 4400 combine, etc.