3-Point Hitch 1210 lift arms don't lift

tree grower · May 7, 2020

The tph on my 1210 w/ 2400 hrs suddenly won't lift. Yesterday the fertilizer spreader settled to the ground when I shut the motor off, but it recovered when I started it back up. Today all worked well for a couple hours, but now-nothing. I checked the pressure at the relief valve manifold and got 1750 psi instead of the required 1850, but I can't believe 100 # low is my problem. The trouble-shooting list in the IT manual mentions possible leakage in the poppet valve, but a poppet valve does not appear in any of the diagrams. The position control lever feels like it is not connected to anything. Before I start disassembling the lift arm housing, does anyone have any suggestions?

JC-jetro · May 7, 2020

good thing is your rig is making pressure so you pump is okay. If poppet was leaking at the pressure relief then it would likely chatter and not allow pressure to be built up. I think there is a good chance is your lift piston seal. Does the 3 point raise if there is nothing hanging in the back and tractor on? I am trying to see the rate the pump is making gpm is greater than the potential leak. why don't y take a few pics of relief valve and lift piston head and where yiu read the pressure. There are many similarities in 1000 series hyd sytem. By the way , it is quite simple to check teh piston seal non-destructively, just need to remove the lift piston head and pull the piston out.

JC,

tree grower · May 8, 2020

JC- thanks for the feedback. I found the poppet valve in the diagram of the relief valve, so that mystery is solved. I started the tractor this AM, and the lift arms still didn't raise. I released one link from the fert. spreader, and the arms started up. Fully disconnected the spreader, and the arms worked OK. As a further test, I attached the weight box (~200 lbs), and they raised with no trouble. Obviously, the problem is intermittent, making it more difficult to diagnose. Your description of how to easily check the piston seal is unclear. Based on the diagram, it appears that the lift arms and rock shaft need to be removed before the piston can be slid out. Am I missing something?

JC-jetro · May 8, 2020

tree grower said:
JC- thanks for the feedback. I found the poppet valve in the diagram of the relief valve, so that mystery is solved. I started the tractor this AM, and the lift arms still didn't raise. I released one link from the fert. spreader, and the arms started up. Fully disconnected the spreader, and the arms worked OK. As a further test, I attached the weight box (~200 lbs), and they raised with no trouble. Obviously, the problem is intermittent, making it more difficult to diagnose. Your description of how to easily check the piston seal is unclear. Based on the diagram, it appears that the lift arms and rock shaft need to be removed before the piston can be slid out. Am I missing something?

Please refer the the pics below, all 1000 series use the same concept. The piston, cylinder (removable), head assembly for the piston./cylinder (removable). Yiiu do not need to mess with the rock shaft only to put in back in the cylinder sleeve and piston in the right direction. Take pic as yiu disassemble so tiy will not get turned around. There are some o-rings that are in the groove. if yi are careful you can take then out on damaged. I just changed mines just because I had them. Kept the old for posterity. Let me know if the pictures are not clear.

Jc,

ps. there is a knob with rabbit and turtle in front of the seat where the shifter is . that is the rate of drop if 3-pt adjustment. Raise the arm, close the valve CCW all the way and f the arm drops then it must be lift piston seal. the seal is on piece, double lipped and made out of nylon. You only get one chance of putting it in ,make sure the orientation is correct.

tree grower · May 9, 2020

Pictures look fine. I see that the piston is not attached to the connecting rod, explaining the rockshaft issue. Before disassembling, I need to describe one more symptom I just remembered. With the fert spreader half full (~400 lbs) and raised several inches off the ground, the hydraulic system pulsed. It felt like the pto shaft was turning slowly but out of balance. The whole rear of the tractor shook moderately, but not for very long, and the pto was NOT engaged. This only happened once, but was very memorable.

JC-jetro · May 9, 2020

so let me ask you, is your transmission hydrostatic? is your pto live? do you know if you have wet PTO clutch or is it mechanical? do you have power steering? I can research it but 1210 can come in different flavors.

tree grower · May 10, 2020

Trans is basic manual, pto is not live (stops when clutch is depressed), am pretty sure clutch is dry mechanical, no power steering. SN is UC-00746. Sorry to be so helpless, but I have so little serious trouble with my equipment that I haven't built up a history of diagnosing these problems.

JC-jetro · May 10, 2020

Ok. So you have a single stage clutch and transmission driven PTO. You will have to preferably in low rpm, fully clutch and then engage PTO lever and let go of clutch to start the pto. In neutral you can have the pto running while stopped. That is exactly how I have it with my Ford 1700. On my kubota PTO clutch is wet and is hydraulically activated. In your case , I see no relation ship with PTO running and Hydraulic system. The pulsing might be related to maybe clogged filter of strainer for the hyd system that might have caused some pump cavitation hence pulsing. when you non-destructively take the lift piston out, if it is damaged then my suggestion is to replace hyd oil and clean strainer including the bottom of diffy floor. when was the last time you have replaced hyd fluid?

tree grower · May 11, 2020

I agree about no relationship between pto and hydraulics, but that is what the pulsing FELT like. I cleaned the filter a year or two ago, but it was pretty clean anyway. I change the engine oil and filter faithfully every year, even though I only put on about 100 hours/ year. I must confess to not having ever changed the hyd fluid. I check it frequently, and it is as clear as tap water. Will change it to be on the safe side. I removed the piston and found no nick in the seal or scoring on the cylinder wall, but the piston slides very easily in the cylinder. I'll replace the seal just to be safe.

JC-jetro · May 11, 2020

tree grower said:
I agree about no relationship between pto and hydraulics, but that is what the pulsing FELT like. I cleaned the filter a year or two ago, but it was pretty clean anyway. I change the engine oil and filter faithfully every year, even though I only put on about 100 hours/ year. I must confess to not having ever changed the hyd fluid. I check it frequently, and it is as clear as tap water. Will change it to be on the safe side. I removed the piston and found no nick in the seal or scoring on the cylinder wall, but the piston slides very easily in the cylinder. I'll replace the seal just to be safe.

it's all good, The work is pretty easy. I would acquire the seal just to have it. if it is no damage see no vaue in changing it. Like I said it is a non-destructive inspection. On the hyd Oil, dip stick oil observation does not give you the complete picture. All transmission and hyd oil is one of the same. The reservoir is your diffy housing, the filter/screen is also over there. You have some ft/minute of velocity of oil in the hyd piping, both suction and discharge but kind of pool of oil in the diffy , so it is where all the sediment settle down in the bottom. The bottom of the strainer sits proud of the diffy floor and that where you have junk built up over years and never shows up in the dip stick. if you have never changed your hyd fluid I bet you that you have built up there. The very first time I opened the drain on the bottom of diffy no oil came out. Made a hook thingy, shoved it from the bottom and what I pulled out look like a dead, decomposed rat. I had about a gallon of oat meal like crap there.