L185DT 3 point lift problem

[jbeenemd]

About two weeks ago I used the L185DT to mow the driveway and an area that had been a garden in past years. Parked it in the barn and Friday went to get it out to mow again. I lifted the front dozer blade up and when I tried to lift the old Woods mower on the rear it would not lift up. Toped off the fluids and tried it again. Still no lift. Took the hydraulic filter out and it did need cleaning. Cleaned in diesel, and reinstalled. Replaced fluid and still no lift. Can't be the pump as my front dozer blade can lift and even has down force to lift the tractor up off the ground. Any other areas to look at? Should I go ahead and drop some bucks for a new filter just to be sure it is not still clogged after cleaning it?

 

[Bulldog]

I wouldn't think it would have broke sitting in the barn. Have you checked hyd lines/fittings or a valve that diverts fluid. I bet it's something simple. Is there anything that you might have hit with your foot as you got off the tractor last time it was used?

 

[ronztractor]

I know some tractors have a rate of drop knob for the 3point sometimes it accidentally gets turned and won't allow it to raise

 

[jbeenemd]

I've checked the lines, topped off the fluids, and also checked the filter and cleaned it. I have a dozer blade up front and it still works. Can lift the front of the tractor up about six inches off the ground with this thing so I know the hydraulic pump is working. There is a "drop knob" down in front of the seat. That is the only "divert valve" so to speak. I have not touched it and is not in the way so did not hit it getting off the tractor. I did play with it AFTER having this problem and have adjusted it all the way in each direction and no results. I am beginning to think that the problem is either a blockage where the lines come off and return from the dozer blade or down inside the rear section of the tractor somewhere. I'll have to take a picture or 2 of where the lines all come together and post them. I am not a mechanic and don't relish the thought of tearing it down.

 

[Bulldog]

If the front blade has couplers on the lines check them to make sure one hasn't come loose or popped out.

 

[aquaforce]

I've checked the lines, topped off the fluids, and also checked the filter and cleaned it. I have a dozer blade up front and it still works. Can lift the front of the tractor up about six inches off the ground with this thing so I know the hydraulic pump is working. There is a "drop knob" down in front of the seat. That is the only "divert valve" so to speak. I have not touched it and is not in the way so did not hit it getting off the tractor. I did play with it AFTER having this problem and have adjusted it all the way in each direction and no results. I am beginning to think that the problem is either a blockage where the lines come off and return from the dozer blade or down inside the rear section of the tractor somewhere. I'll have to take a picture or 2 of where the lines all come together and post them. I am not a mechanic and don't relish the thought of tearing it down.

Welcome to OTT.

If you turned that knob under the seat with no change in the 3pt performance then there is a possibility the prob is right there. That knob should almost make the 3pt not go down at all if closed up. In hydraulics that knob works like what is called a "snubber valve"; it controls the amount of fluid let by for more or less control of the hydraulic function and or properties.


What happens if you manually raise the 3pt some and then hit the function to raise? My thought here is leakage at the ends of the stroke of the piston. There can also be a crack in the bore where the 3pt is fine in some places but bad in others and usually at the ends of the bore.

 

[jbeenemd]

@aquaforce, I understand what the "knob" does. The problem is that the 3 point DOES NOT move at all. No up, stays down and seems to not be getting any flow to it at all. NOTHING at all from the 3 point, while I have full normal function up front. That makes me thing that the problem is within the 3 point system itself.

 

[aquaforce]

@aquaforce, I understand what the "knob" does. The problem is that the 3 point DOES NOT move at all. No up, stays down and seems to not be getting any flow to it at all. NOTHING at all from the 3 point, while I have full normal function up front. That makes me thing that the problem is within the 3 point system itself.

Ok another thought. Is your front and 3pt tied together with a manifold block where both functions would work at the same time or are they shuttle shifted meaning only one would work at a time when both functions were held, before the 3pt quit?
If they are shuttle shift controlled then the shuttle valve can be stuck where all the flow is only going to the front.


If nothing at all happens at the knob there could be a problem with fluid bypassing at that cap. One way to tell if fluid is bypassing is to hold the function and listen for flow, the slight hiss sound of fluid moving through the passages in that cap. Also any time fluid bypasses heat is created, as a principal of hydraulics. By letting the tractor run for a few mins and holding the function handle you can feel around the hydraulics for heat build up to locate an area of bypass.


In the 3pt itself, can you manually raise the 3pt bars up half way and then hold the function lever to raise and anything happen? I have seen where the 3pt had a problem in the system and it would not lift from the bottom of the stroke but part way up it would. If that is the case it is time to tear down the 3pt for repairs of the bore, piston, rings etc, something that is not holding.

 

[jbeenemd]

Ok, I have no idea of what a manifold block is, so can't answer that question. Before all this happened, I could raise the 3 point and then use the front blade as well without any problems. I have a set of controls mounted up front by the throttle with which I can raise/lower the blade and turn it left/right.

I will try running the tractor on Saturday for a while to let it warm up and then feel around the knob to see if it warms up. Right now I have no lift at the 3 point at all. IT IS DEAD!!!

Will have to find a way to lift the arms up enough to remove the woods mower and set on some blocks then can try lifting the arms manually.

I did take some pictures of where the lines from the front blade tie into the hydraulics on the left side of the trans just below the seat.

 

[gpreuss]

There is a screen down in the bottom of the transmission case, pretty much below the seat on the right side, covered by a plug. You have to drain the oil to get it out. Pulling the plug drains the oil... If that is not what you are talking about when you said you cleaned the filter, then that is something to look at.
As far as I know the 3ph and that hydraulic block pictured are on a common line. If the front blade works, the 3ph should. Possibly the linkage is bad?
Another thought is that the control valve for the blade is supposed to flow in neutral. If that flow is blocked, it can be your problem. A way to check is to simultaneously lift the 3ph, and lift/lower the blade. While the blade is moving, the 3ph may jerk up a bit. But you have probably already tried that.
The tractor came with a block where your hoses are connected in the rear on the left by the seat. If you happen to have the original block you might put it back on, and eliminate the front blade from the problem. The original block had a passage in it, that just allowed flow from the pump back to the reservoir.
Do let us know what you finally find.

 

[jbeenemd]

1) I have cleaned the screen at the bottom of the trans. this did nothing for the 3 point.
2) The front blade worked before and after the cleaning of the screen.
3) As far as the linkage, what do I look for to tell it is bad?
4) I've checked the return from the hydraulic pump and have good flow but not yet checked or isolated the front control to see if I am getting flow through there while not in use. Will check this today.
5) I bought this used from my father-in-law who bought it from the estate of his friend who used it to push snow on parking lots. That block is long gone. I had already thought about trying to get something like that to isolate the front from the system.

Thanks for the extra suggestions everyone. I am not a mechanic so this is learning experience for sure.

 

[aquaforce]

Will have to find a way to lift the arms up enough to remove the woods mower and set on some blocks then can try lifting the arms manually.

I did take some pictures of where the lines from the front blade tie into the hydraulics on the left side of the trans just below the seat.

I know hydraulics pretty well but I don't know the schematic of the L185 enough to know where to check the pressures or component location so I can't tell from the pic if the block has a shuttle. My guess is it does not.

I didn't know you had something still on the 3pt, when I was talking about manually raising the 3pt arms to see if the function would catch up. Once you try that tell us what happens.

 

[jbeenemd]

I had some time after work today to take everything apart where the hydraulic hoses from the front blade tie into the 3 point. That block is a solid piece of aluminum that allows the hoses to tie into the rear 3 point. Took off the 3 pieces below the block and took them apart and cleaned everything. Took the valve out and cleaned it. Put everything back together and still nothing. There is no blockage there. Front blade still works. Also turned "the knob" all the way from one side to the other testing the lift and still nothing. I did jack the arms up a few inches with a floor jack and the 3 point lever in the raised position. The arms stayed up afterward even with it loaded down with the woods mower attached. So that part of the 3 point still works. I am beginning to think that the problem is behind where "the knob" is. Maybe this weekend I will get brave enough to take that apart. Going to get my shop manual out to take a look at the diagrams.

 

[Bulldog]

I may be wrong but the knob doesn't have anything to do with lift. It only controls the rate of drop or stops the drop completely. I have all mine set so the arms drop real slow to keep from slamming implements on the ground. The arm raise at the same rate no matter how slow they lower.

 

[jbeenemd]

I am at a loss to explain why the front hydraulics work and the 3 point does not. Working on the assumption that there is a valve not functioning somewhere in the system. There is a valve on the left side where the lines for the front come off. I took all that off today, cleaned, inspected, and reassembled everything. Everything looks normal per diagram in the shop manual. I have had suggestions that if the knob was closed that the 3 point would not lift nor drop. Thinking maybe, just maybe there is something in that system that is stuck closed and the 3 point is not getting fluid to it.

 

[Bulldog]

I'm pretty sure the knob only controls drop and has nothing to do with lift. It looks like if the knob stopped the lift when you move your control to the lift position it would make some noise such as fluid by-pass.

Have you inspected the controls to make sure everything is hooked up and moving like it should. I had a high/low shifter quit working one time. Lever moved but wouldn't shift the transmission. The shifter handle was working fine but the shaft it was supposed to move was still. I was lucky and a roll pin fixed my problem. Just trying to eliminate all the simple stuff first.

 

[jbeenemd]

I have checked everything from the pump, to the front controls for the front blade, to the return and took everything apart at the point where the outflow and return from the front hydraulics tie into the 3 point. I have come to the conclusion that something is amiss behind where the "knob" is. Meaning like you said about the your shift lever, maybe something with the 3 point lever not interfacing correctly. As far as I can tell the best way to get into this area is to take off the plate with the "knob" attached to it. Could not find anything in my abbreviated shop manual about this.

Maybe someone above was trying to give me some inspiration last night as when I went to the garage behind the house I heard something running. Could not hear my air compressor running, so what the heck was it. Well I found the electric motor running but the pulley was not turning. (Dang one more thing to fix) So maybe the shaft for the 3 point is not turning or a gear or what ever attached to it is sprung???

 

[jbeenemd]

Got an IT Shop Manual and looking at the diagrams. Looks like my lift problem is in the position control valve. Has anyone tried tearing into their position control valve for any type of service?

 

[aquaforce]

I almost did when I got mine because of a broke bolt. It drilled out so I didn't have to disassemble anything.

I think your on the right track since the flow and control are all in that top cover.
Have you checked the rock shaft and the control shaft of the 3pt lever very well? Those are base to this function.

 

[jbeenemd]

OK, project update. It was the position control valve. Got the tractor apart and the valve out but for the life of me I could not get it apart to inspect it. Did find a used replacement from an L245 and got it installed. Pulled a muscle in my back trying to set that piece of iron back on the transaxle. Had to wait until this weekend to get it back together. Just in time as I am going in for rotator cuff repair on Friday. Will be out of service for a while.