New Holland 2120 no forward or reverse

[MrTea]

Hello,
I just purchased a 1999 New Holland 2120 that will not operate in forward or reverse. The loader works and has plenty of power. The power steering does not work. I did some research and read where a couple people had a diode go out in their control module. I checked this and that particular diode was fine. It was clear someone had removed the module before me(mounting bolts loose,pried on box)
I do have the flow chart for the HSS but the first step is to test the hydraulic relief valve pressure. Is there a test port? TSC for a gauge? Any other suggestions where to start?

 

[RickB]

Check to see if the PTO works when you try to move the tractor. If not the main clutch is out. Power steering is a dedicated system and a separate problem.

 

[MrTea]

Check to see if the PTO works when you try to move the tractor. If not the main clutch is out. Power steering is a dedicated system and a separate problem.

With the tractor in gear and moving the shuttle shift forward and reverse the pto appears to operate as it should. I don't have an attachment available to put it under load if that matters? The PTO shifts in and out solidly, the shaft coast to a stop when disengaged and you cannot slow it down by hand(not a lot of load I know)

Scott

 

[RickB]

If the main clutch were the culprit the PTO shaft would not turn at all when the tractor was refusing to move. Sadly your problem lies within the EHSS system.

 

[MrTea]

I appreciate the help. Each part I can eliminate gets me one step closer to finding the culprit.

 

[MrTea]

Today I found a wire off the switch connected to the HSS lever, no help. I found a ground wire off by the solenoids, no help except I did start seeing a signal to the solenoids when the lever is moved. When the lever is moved the test light is bright then dims a little. This seams like the control module is working. If I pull a solenoid could I see it operate?

 

[MrTea]

I just checked the solenoids and they seam fine. I read the the voltage is suppose to drop to 5v so that would explain the dimming of the light. There is a cable that ges from the clutch to just in front of one of the solenoids. Mine pulls out when the clutch is depressed but doesn't go back in unless you push it. Does anyone know what this is for?
At this point I would say my control module is good unless I am missing something? What could be next?

 

[MrTea]

This may be it$$
https://www.tractorbynet.com/forums/parts-repairs/283016-splitting-ford-2120-a.html

 

[MrTea]

Except... My clutch does work. Also I think it has separate forward and reverse hydraulic clutches so I wonder the likelihood of them both being out.

 

[RickB]

Except... My clutch does work. Also I think it has separate forward and reverse hydraulic clutches so I wonder the likelihood of them both being out.

Or no regulated circuit pressure or flow to and through the valve to lock up the F and R clutch packs. Time for a service manual. If you get an OEM repair manual be sure to get the supplement that covers the EHSS variation you have. It is separate from the 1920/2120 manual which predates your tractor.

 

[MrTea]

Any suggestions on a good manual?

 

[spitter]

Buy shop online $300 paper copy or like $50 for cd or pdf. Just google NH 2120 service manual:drink:

 

[MrTea]

I bought the manuals, the gauges, read a lot then started testing. The first test showed no pressure at the line going into the transmission control valve.
I was told and read the power steering was a separate system but it seamed odd they both quit at the same time. I traced all of the hydraulic lines to see what was up. My pumps are different than what the manuals show. Mine has a pump behind the timing cover for the loader etc then 2 pumps in front of the cover for steering and the transmission. I made sure there was a supply of oil to both pumps(there was) and the I checked for pressure coming out of the pumps, nothing.
I pulled the pumps, the splined shaft is sheared off. Maybe awesome. I have to figure out where to get it fixed or get the part then see if it fixes everything. I do wonder why it sheared.

 

[RickB]

Surely better news than needing clutch packs overhauled.

 

[grcutter]

I bought the manuals, the gauges, read a lot then started testing. The first test showed no pressure at the line going into the transmission control valve.
I was told and read the power steering was a separate system but it seamed odd they both quit at the same time. I traced all of the hydraulic lines to see what was up. My pumps are different than what the manuals show. Mine has a pump behind the timing cover for the loader etc then 2 pumps in front of the cover for steering and the transmission. I made sure there was a supply of oil to both pumps(there was) and the I checked for pressure coming out of the pumps, nothing.
I pulled the pumps, the splined shaft is sheared off. Maybe awesome. I have to figure out where to get it fixed or get the part then see if it fixes everything. I do wonder why it sheared.

Mr. Tea,
My 2120 has the same 3 pump configuration that you describe. The pictures in the service manual do not match at all.
I'm afraid that I may have the same problem but not with the power steering pump but the HSS pump that is connected to it. I have not opened this yet as it is appears to be a LOT of work!
Were you able to find parts for this?
My search for parts comes up with either a seal kit or the whole pump a$$embly, but nothing for the internal parts.
If I did my homework correctly, this pump is SBA340451001 which is equivalent to SBA340451000.

 

[grcutter]

BTW, my pump is also a KYB (Kayaba) model number model KRP4-12-5ANBHM

 

[kbento7070]

My 1997 2120 had this issue. Wasn't the clutches or anything like that, turned out to be a bad diode in the computer module! The computer module is under the housing for the steering wheel, the "Do not remove" sticker on it, you have to remove and peel off that sticker to open it up. In there, test the diode, bet one is bad. It controls the solenoid for the forward abd reverse hydraulic flow. Just unsolder the bad one and solder in a new one. Pay attention to the direction of the diode, they are directional!!

Go to ebay and search for:
U19E / CROSSES TO ECG580, / CERAMIC DIODE / 3 PIECES (qzty)

Thats the one that'll work. Quick $15 fix.

Hope this helps future stuck 2120's