Is 3 Pt Hitch Leakdown Normal?

[genusCastor]

I recently bought a 2003 Mahindra 3510. Last night I put an implement on the 3 point hitch for the first time, and noticed it drops an inch or two every 20 seconds, then lifts back up. A continuous cycle: drop down, lift up... I haven't had a load in the FEL yet, so I don't know if it exhibits the same behavior or not.

I asked the guy I bought it from and he said that a certain amount of leak down/lift up cycling is normal. Is it?

- djb

 

[Bousez]

I do not think so....... !!!!
there is something wrong for sure ......

 

[Jay4200]

I recently bought a 2003 Mahindra 3510. Last night I put an implement on the 3 point hitch for the first time, and noticed it drops an inch or two every 20 seconds, then lifts back up. A continuous cycle: drop down, lift up... I haven't had a load in the FEL yet, so I don't know if it exhibits the same behavior or not.

I asked the guy I bought it from and he said that a certain amount of leak down/lift up cycling is normal. Is it?

- djb

No. If I have my rake all the way up when I shut my tractor down, it'll be an inch or two lower the next morning. That's normal.

JayC

 

[genusCastor]

How would I go about troubleshooting the problem? I'm not a pro mechanically, but I can do basic repairs... Would there be a valve that could be removed and checked?

- djb

 

[J_J]

Could it be the draft control.

A hydraulic draft control system for use on a tractor and having a pilot valve regulating flow and pressure for automatically operating a draft control valve. The pilot valve opens and closes in response to draft loads sensed on the tractor to control the opening and closing of the control valve for raising and lowering of an implement on the tractor.

Quote:

On a tractor that has draft control, the draft control lever sets the sensitivity of the draft system. "Draft" refers to the hydraulic system's ability to sense and react to the pulling load of the 3-pt hitch.

On your tractor, the tractor,s top link(center link) clevis can move in and out slightly. It is actually connected to the hydraulic control valve inside the tractor.

If you were pulling a plow, and the plow hit an underground rock or root, the plow would be tilted forward, which pushes the top link "in". If the draft lever is set to the most "sensitive" position, the hydraulic system would automatically raise the lift momentarily and then return the plow to its original position (based of the position of the "position" lever). All of this happens without you stopping or making any adjustments.

If you have it set too sensitive, the plow will raise up all of the time under even the slightest loads. You may have noticed that if you move the draft lever to the top, the lift might raise all the way up suddenly. If you have it set too low, the plow won't raise and you could get caught on the root or tear something up.

On Fords and Masseys (and most other tractors) draft sensitivity is highest at the up position and lowest and the bottom position of the draft lever.

For most bush-hoging, mowing, blading, discing, planting, etc., the draft control isn't even used. I'd set the draft lever about 1" up from the bottom, set it there with the stop, and never touch it again.

As tractors get older, the internal linkage gets worn out and the draft lever's position varies. So, the actual placement of the draft lever isn't that critical in your case. Just keep it on the lower half.

 

[doall]

I know most Mahindra's have the draft control, so I was going to suggest that too. J J got you covered.

 

[genusCastor]

OK, so I may just not have the draft control set correctly(?) I must confess, I have not really understood exactly what the draft control is for. I grew up with an old Massey Ferguson 35 which had a draft lever, but I never used it (or forgot what it did)...

I found this website that seems to be a good 3 point hitch tutor.

Now, with all of this draft action going on, we've got to slow the lift system down some, or we'll end up with a rapid, out of control oscillation of the lift arms going up and down.

Reckon I need to 'play' with the draft and see if the prollem might be user error. :laughing:

- djb

 

[sweettractors]

Most tractors have a draft control lever that you can use on or off. If you have one, make sure that it is in the off position. About the only time you need draft control is when you are plowing. Ken Sweet

 

[LAWALLSTRACTOR]

I recently bought a 2003 Mahindra 3510. Last night I put an implement on the 3 point hitch for the first time, and noticed it drops an inch or two every 20 seconds, then lifts back up. A continuous cycle: drop down, lift up... I haven't had a load in the FEL yet, so I don't know if it exhibits the same behavior or not.

I asked the guy I bought it from and he said that a certain amount of leak down/lift up cycling is normal. Is it?

- djb

Sounds like there may be some trash lodged in the relief valve. Chain the 3PH to something it can't lift and try to lift it. This should open the relief valve and flush it out. I am not sure it is your problem but it may be. Let us know if this works.

 

[genusCastor]

Chain the 3PH to something it can't lift and try to lift it. This should open the relief valve and flush it out.

Yesterday I was pulling out fence T-posts, and on one of them the lift couldn't pull it up. While the 3 pt system was under that strain, I noticed it started oscillating (leak down/lift up) just like it did with the implement on it the other night.

Also, when I shut the tractor off, the 3 pt hitch drops to the ground in 15 minutes or so, without a load on it...

I also checked the draft. There is no "OFF" position, but I placed it on the minimum setting (1 out of 5), and it still seems to oscillate. It definitely oscillates on the maximum setting (5).

- djb

 

[J_J]

It appears you have a leak as others have said. Some 3pt cylinders are not as good as others, and as they wear, the situation gets worse. Most of them will leak soon or later. New seals/o-rings maybe. Or, trash in the circuit causing leak down.

 

[CompactTractorFan]

I noticed after I turn off my tractor and it sits a while everything seems to "leakdown" (Mower, Backhoe...etc...). Also the mower seems to drop some while I'm driving around especially in rough terrain. Is that normal? This on a BX25. Oh, and I'm not trying to threadjack...

 

[jinman]

To help isolate the problem, I think you can do a test. You should have a needle valve that adjusts how fast the 3PH normally drops. Raise the 3PH and shut that needle valve completely off. Then, shut off the tractor and watch the 3PH. If it drops, the problem is likely to be lift cylinder seals. If it does not drop, then the problem might be in the 3PH control valve.

 

[mmurphy]

Is it possible to look in casing with tractor off to see 3ph cylinder? If you can, possible to see dripping coming from end of cylinder.

 

[dfkrug]

No one has mentioned the 3-pt load check valve yet. On my Deeres,
they are on the top of the 3-pt cylinder housing and have large hex
heads. When removed, there is a spring and ball in there. It is
separate from the relief valve, which can look similar.

I do not know your machine, but all my CUTs have had load check
valves. The ball could be corroded or dirty.

 

[genusCastor]

To help isolate the problem, I think you can do a test. You should have a needle valve that adjusts how fast the 3PH normally drops. Raise the 3PH and shut that needle valve completely off. Then, shut off the tractor and watch the 3PH. If it drops, the problem is likely to be lift cylinder seals. If it does not drop, then the problem might be in the 3PH control valve.

I finally got a chance to test this, and it does drop with the valve shut off. So that seems to indicate a cylinder seal problem(?) Is there something else to test to isolate the problem?

Thanks, everyone.

- djb

 

[jinman]

I finally got a chance to test this, and it does drop with the valve shut off. So that seems to indicate a cylinder seal problem(?) Is there something else to test to isolate the problem?

Thanks, everyone.

- djb

It is possible that your Mahindra is mechanized much like my NH, a Kubota, or a Deere. Without seeing a diagram, it's really speculation, but experience would say that it is probably similar to all these systems. I'd surely post in the Mahindra forum so you can get an accurate comparison from other Mahindra owners. They can verify whether your dealer is giving you good info or not. If this were normal, I'd expect to hear a lot about it in the Mahindra forums.

That said, Dave raises a good suggestion about the load check valve. If you can gain access to the valve and check it for cleanliness, it sure wouldn't hurt anything to do that check. On my New Holland, the needle valve is in parallel with a ball check valve and high pressure relief valve. If the ball valve is leaking it would allow the lift to drop, but you have to consider that this ball valve gets "washed" everytime you lift your 3PH. Surely, trash would have a hard time building up there in a normally clean system that showed no signs of contaminated fluid. I think it is far more likely that you have a slow leak in your lift cylinder seal.

 

[genusCastor]

...trash would have a hard time building up there in a normally clean system...

Trash in the system has been mentioned before and I'm curious, how could anything get in? I'm guessing it could only be when someone has the system open and lets dirt, etc., get in(?)

I'll post a question to the Mahindra folks. :thumbsup:

- djb

 

[dfkrug]

If the ball valve is leaking it would allow the lift to drop, but you have to consider that this ball valve gets "washed" everytime you lift your 3PH. Surely, trash would have a hard time building up there in a normally clean system that showed no signs of contaminated fluid. I think it is far more likely that you have a slow leak in your lift cylinder seal.

That's a good point.

Also, the cylinder is single-acting, so a leaky piston seal would indeed
cause the three point to sink on its own (vs. for a DA cyl).

As for a non-functioning load-check RV, I imagine that the spring could
break, or a long time of non-use could allow corrosion or sediment buildup. I
once found corrosion in an Iseki hyd PTO diverter valve, which was not
used for a very long time. I know non-use does not apply to the OP's
case.