Farmall 120c DEF problems

[ryangpayne]

Just bought a new farmall 120c. It is a left over 2023 model and has 12 hours on it so it has been sitting on the dealer lot of a good while. 
 

went to back it off the truck and it has a couple warning lights on. One that the book says is for poor DEF quality and the other is for a DEF injector fault as far as I can tell. The dealer is being no help so I thought if it was something simple I’d just fix it. This is my first tractor with DEF. 

i drained the def tank and refilled with new clean fluid and I pulled the def injector out and cleaned it with deionized water. These things made no difference. Is there a way to reset these lights and warnings after I do work like that or should they go off on their own if the issue is fixed? Does anyone have any other ideas to try before I have to haul it back to the dealer? Thanks!-Ryan

[Ihfan4life]

Not sure, but being  a DEF issue it’s most likely a dealer computer to reset the light, providing you fixed the issue…

[TroyDairy]

@HydroTek

[756puller]

Probably have to reset the engine counter with dealer laptop. Have had a Few problems with the wema sensor in the tank not reading good def quality when it's actually good. 

[ryangpayne]

Thank you guys for the information. I guess I’m glad I got a small enough tractor I can haul it to the dealer easily. I’m starting to dislike this tractor already lol. 

[756puller]

Oh they can be good little loader tractors. Got a seed corn research place that has three of them equiped with autosteer and running hydraulic drives on the planter. Needless to say these little tractors are maxed out for their capabilities with these guys and they always break stupid crap. Had a 105u a few years ago the hydraulic pump locked up the engine and bent pushrods which basically ruined the engine. Got it hauled into the shop diagnosed what was wrong. Started the process of tearing apart for a new engine. And these idiots were calling every half hour wanting to know the progress on it. The customer started calling everyone they could to try to light a fire under this project to get it done.  

[Cdfarabaugh]

Dealer is no help help?  What idiots run these places?  Holy crap it's surely under warranty with 12 hours being a leftover '23 that sat around and if not at least take a look at it just to keep a customer happy! 

[CIHTECH]

On 1/11/2025 at 6:28 PM, ryangpayne said:

The dealer is being no help

I would be contacting CaseIH, tomorrow morning if not sooner.

[ryangpayne]

Here is why this is a little of an odd situation. I bought this tractor from a dealer 300 miles away from me in south Texas. I specifically wanted a 2wd with no loader and this salesman is the only one I could find that would go to the trouble to locate me one. I’ve bought another farmall from him about 5 years ago.  He did locate me one, he claimed the only one in North America, at a dealer in Binbrock, ON Canada. So I paid my salesman for it and he had it shipped straight to me. His dealership never laid hands on it.
 

But obviously the dealer in Canada never took care of the problems the tractor had before they loaded it up. they didn’t even top off the antifreeze or rear end oil, and the front wheels are not adjusted right either. I called the salesman I ordered it from and he claimed he would have service manager call me right back but that was last Wednesday and I never heard a thing back. 
 

 I can load it up and haul it to my local dealer 40 miles away and I’m sure they will get it fixed. It seems like a lot of trouble for a new tractor that should’ve been right when it arrived. That’s why I was hoping it was something simple I could fix without much trouble. 

[HydroTek]

6 hours ago, 756puller said:

Had a 105u a few years ago the hydraulic pump locked up the engine and bent pushrods which basically ruined the engine.

Not saying this didn't happen , so dont jump there

Just curious how the hydraulic pump failing could affect the pushrods ?

[HydroTek]

24 minutes ago, ryangpayne said:

Here is why this is a little of an odd situation. I bought this tractor from a dealer 300 miles away from me in south Texas. I specifically wanted a 2wd with no loader and this salesman is the only one I could find that would go to the trouble to locate me one. I’ve bought another farmall from him about 5 years ago.  He did locate me one, he claimed the only one in North America, at a dealer in Binbrock, ON Canada. So I paid my salesman for it and he had it shipped straight to me. His dealership never laid hands on it.
 

But obviously the dealer in Canada never took care of the problems the tractor had before they loaded it up. they didn’t even top off the antifreeze or rear end oil, and the front wheels are not adjusted right either. I called the salesman I ordered it from and he claimed he would have service manager call me right back but that was last Wednesday and I never heard a thing back. 
 

 I can load it up and haul it to my local dealer 40 miles away and I’m sure they will get it fixed. It seems like a lot of trouble for a new tractor that should’ve been right when it arrived. That’s why I was hoping it was something simple I could fix without much trouble. 

So yeah , laziness on the part of the dealer that sold the tractor -- but was probable treated as a transfer

The emissions system is still under warranty so your dealer can fix it
the laptop needs to be connected and run the system thru the def dosing tests
...and to reset the codes

wema failure could be from sitting and the quality sensor has "failed"
the sensor is a pain to wash out and get working again ...but possible
usually we would just replace the wema

[756puller]

1 hour ago, HydroTek said:

Not saying this didn't happen , so dont jump there

Just curious how the hydraulic pump failing could affect the pushrods ?

Hyd Pump ran off timing cover, pump locked up and brought cam to a halt.

[HydroTek]

2 hours ago, 756puller said:

Hyd Pump ran off timing cover, pump locked up and brought cam to a halt.

Thanks for the reply
I had one of those 'U' models that the gears wore thru the side of the pump -- didn't break anything tho