Wrong Type Valve?

[Sockwell]

When I bought my L5740, I had the dealer add two rear remote valves. I recently installed a Top Link cylinder. I'm wondering if I have the wrong type valve for this. This morning I was using a rotary cutter. When I would try to raise the cutter, the lower links would lift the front of the cutter. The top link extends rather than staying at a fixed length, leaving the rear cutter wheels on the ground. When the cutter is lowered, the lower links lower and the top link cylinder retracts. Do I have the wrong type valve?

 

[TripleR]

Does the top link extend/retract when you move the lever?

 

[J_J]

If you are only moving the 3pt lever, and just raising the mower, the top link shaft should not move .

The top link is controlled by the remote valve. It should be locked.

Now if your seals are gone, then maybe.

Just operating the top link lever, does the shaft move in and out, and hold?

Is your top link cyl plugged into the same spool, such as A work port and B work port.

 

[Sockwell]

The top link does not extend/retract with the lift lever. Though the tractor is about 14 months old, today was the first time anything had been plugged into either rear remote. The top link is new and was just installed yesterday.

When I finished mowing the pasture, I was doing a little cleanup with the grapple. I noticed that though the lift was raised, the wheels were on the ground. I retracted the top link to lift the back of the mower. I didn't move the lift lever. I noticed a few minutes later that the wheels were again on the ground.

I then raised and lowered the lift a few times and noticed that the top link extended and retracted as the lift went up and down. I don't think the system was sending fluid to it. It was more like it was floating. I'm starting to think that either the cylinder or the valve has a leaking seal, allowing fluid to bypass. The only thing I knew to do was to raise the 3PH, fully retract the top link, then lower the 3PH. I then unplugged the hoses.

I've left the mower sitting this way, with the lift down and the rear of the mower In the air. I'll look in the morning to see if the rear of the mower is on the ground. If so, the cylinder is leaking. If not, I'll repeat the test tomorrow with the hoses plugged in. If so, wouldn't that point to the valve? Will these tests tell me what the problem is? Are there better ways to find the problem?

 

[J_J]

Wait a minute, is one of the remote valve spools a float spool?

That is what it sounds like.

 

[Sockwell]

I'm not sure. That was the reason for the question about "wrong type valve". The paper work doesn't say the types of valves. I've called the dealer and he's going to look up the serial number and see what valves were installed. He did say that the float type valves have a float position all the way forward, similar to the float position on the loader. If that's the case, neither is a float valve. That is what it's acting like, though.

 

[MtnViewRanch]

If you just put the top link on, how many times did you fully cycle it? It may still have air in the cylinder. It needs to be fully cycled 10-20 times to be sure that all of the air is purged out of the cylinder and hydraulic lines.

 

[J_J]

If the cyl ports are in the vertical position, the air should be purged rather quickly usually in 1 or 2 strokes.

If the base end of the cyl is straight up or down, the only air that remains is the space from the cyl port to the cyl end.

The only way that a cyl rod will just move by it self is something has released the spool from its locked position.

Problems could be bad seals,

Bad spool.

When a spool goes to neutral, it usually locks the cyl.

 

[MtnViewRanch]

If the cyl ports are in the vertical position, the air should be purged rather quickly usually in 1 or 2 strokes.

If the base end of the cyl is straight up or down, the only air that remains is the space from the cyl port to the cyl end.

The only way that a cyl rod will just move by it self is something has released the spool from its locked position.

Problems could be bad seals,

Bad spool.

When a spool goes to neutral, it usually locks the cyl.

I agree that it "should" take only a few complete cycles, but I have seen it take over 10 cycles to get the air out.

 

[oldnslo]

When I bought my L5740, I had the dealer add two rear remote valves. I recently installed a Top Link cylinder. I'm wondering if I have the wrong type valve for this. This morning I was using a rotary cutter. When I would try to raise the cutter, the lower links would lift the front of the cutter. The top link extends rather than staying at a fixed length, leaving the rear cutter wheels on the ground. When the cutter is lowered, the lower links lower and the top link cylinder retracts. Do I have the wrong type valve?

Have you tried connecting the top link to the other set of remote QD's?

Or set the top link in some position and unplug the hoses from the tractor QD's now raise the implement with the 3PH. Does the top link move? If no then it is something in your valve. If yes you either have a lot of air in the top link or a bad seals on the top link.

 

[Kaliburz]

Here is a dumb test. Switch the quick disconnect hoses.

If your mower still goes down, then most likely be your seals. If the mower raises, then you know your control valve is "leaking". I had that happen on a tractor once. One side would leak so it would slowly extend or retract the cylinder depending on how it was connected.

Now cycling the cylinder XX times should remove the air. Depending on location of the ports, you should keep the ports high so the air will "float" to their location and in theory, get cycled out.

 

[J_J]

Cyl don't normally move when all valve levers are in neutral, and the centering springs are doing their job, as the fluid has no pressure or very little pressure from pump to tank..

Moving the spools and having something provide resistance is what causes the pressure to be developed.

 

[Kaliburz]

Cyl don't normally move when all valve levers are in neutral, and the centering springs are doing their job, as the fluid has no pressure or very little pressure from pump to tank..

Moving the spools and having something provide resistance is what causes the pressure to be developed.

Correct, they don't....when everything is working correctly or not worn (but w/ it being new....it should not be an issue).

Wait, Kubota's are open center hydraulics aren't they. I forget more and more tractors are open center now a days.

My old Deere is a closed center system and the factory installed control valve had issues. OEM Deere's different then the traditional push/pull hydraulic valves. Being closed center, you have at least 2000psi available all the time....

But still, if it's not the valve, then it probably is the seals in the cylinder. Just because it's new....doesn't mean that something isn't bad.