Hydraulic Top Link Drawbacks

[Ford850]

First thing to do so that you don't have to guess if the cylinders or the valves are the problem is to have the implement on the ground, set the hydraulics how you want them. Then un plug the QDs, mark or measure the cylinder rods so that you will know if and how much the rods extend under a load. Raise the hitch so that the implement is in the air. Watch for 10 or 15 minutes. If the rod extends more than 1/16"- 3/32" in that time frame then the cylinder needs to be looked at. This is not to say that your valves don't have a problem also, but it lets you know if the cylinders are bad and it gives you a place to start at when trouble shooting. With no to little movement, then the cylinders are fine and the problem is with the control valves.

In my experience with the product that I sell, almost always the cylinders are fine and the leakage is from the control valves. How you choose to deal with that is for you to decide.

Thanks Brian. I plan to do that test the next time I have the rotary mower attached. I have put it off till now so I could get a feel for how much it was dropping, etc. Or maybe I was in denial.
The valve for the bucket leaking is understandable to me, since I've used it for 7 years. But the remote valves are practically unused until now. I'll start another thread with questions on that when I get some testing done.

 

[Ford850]

The only 'problem' with a hydraulic top link is when you're not using it. The 'hook' that holds the stock toplink up and out of the way is too small to hold the larger hydraulic toplink.

I noticed that after installing mine, with nothing to rest it on.
I made a replacement hook from some 3/16" (?) rod. Made the same size as the original except with a larger hook. It works great.

 

[MtnViewRanch]

Further to the OP's question about drawbacks, I recall something a tractor dealer said to me that I'm curious about. He wasn't a fan of hydraulic top links for use with very heavy implements, such as a large rotary cutter. He described a case where an owner with a Cat. 2 hydraulic top link was carrying his big rotary cutter in the fully raised position. He went over some hummocks too fast, causing the cutter to bounce up and down so violently that the cylinder was seriously damaged. Don't know more details, but it struck me as a pretty extreme case, and didn't deter me from going hydraulic. But I mention it here because the dealer felt that a conventional top link is less vulnerable with a big rotary cutter. Anyone else who's heard that?

To the best of my knowledge, NONE of the many different hydraulic links manufactured are weaker than the OEM manual units that they replace. Maybe only as strong, but none that are weaker.

 

[bumperm]

When doing the disconnect quick connect creep down test, be sure to check the quick connect for leakage too.

I tied a short loop of nylon rope around my hydraulic top link. Slipping the loop over the original hook holds the top link up.

bumper

 

[dfkrug]

He described a case where an owner with a Cat. 2 hydraulic top link was carrying
his big rotary cutter in the fully raised position. He went over some hummocks too fast, causing the cutter to
bounce up and down so violently that the cylinder was seriously damaged.

I believe you can damage a HTL that way. My tractors all have a shock-RVs in the 3-pt cylinder ckt to avoid
such damage to a fairly robust 3PT cylinder. It is set to almost 3000psi on my Kioti. Driving any tractor
fast (over 10MPH) on less-than-smooth roads can put huge tension stresses on the HTL cyl, too. I would
not be as concerned about sideways stresses to the HTL since they have Heim joints at both ends. To
avoid these stresses to the HTL, drive slower, put a workport RV in the system, or buy a larger diameter
HTL cylinder.

Threaded OEM toplinks have all been pretty wimpy, in my experience. The many rental tractors I have
owned always had somewhat buckled threaded toplinks from aggressive box blade use. The $25
threaded aftermarket toplinks I have bought have all been stouter than the OEM units.

I love hydraulic toplinks, and the downsides are few. I did prefer my 2nd one, which I made to a
custom length, versus the off-the-shelf unit (my first one). Customizing the open and closed
length to your tractor and implements is nice.

 

[Rocky Hoffler]

P. O. check valves also called holding valves are some times external if they don't bolt directly to machined part of cyl they need to be plumed with steel lines from valve to cyl on larger diameter cyl the checks are ported in cyl and thread in with a oring seal and are sometimes adjustable working in the utility field all aerial units use check valves. have to be careful when servicing a cyl with a check valve as they hold pressure and just operating control will not relieve pressure and you have pso or pressure squirting out.

 

[/pine]

Hydraulic Top Link Drawbacks

Seeing the thread where it is...I digress backwards...

It may be a "drawback" to some...but...the tractor must be running to move/adjust a Hyd.T.L. when installing/removing attachments...but IMO just being able to reach up and move the top (or side) side link when having to fudge a heavy implement into position...is worth it...

 

[Ford850]

First thing to do so that you don't have to guess if the cylinders or the valves are the problem is to have the implement on the ground, set the hydraulics how you want them. Then un plug the QDs, mark or measure the cylinder rods so that you will know if and how much the rods extend under a load. Raise the hitch so that the implement is in the air. Watch for 10 or 15 minutes. If the rod extends more than 1/16"- 3/32" in that time frame then the cylinder needs to be looked at. This is not to say that your valves don't have a problem also, but it lets you know if the cylinders are bad and it gives you a place to start at when trouble shooting. With no to little movement, then the cylinders are fine and the problem is with the control valves.

In my experience with the product that I sell, almost always the cylinders are fine and the leakage is from the control valves. How you choose to deal with that is for you to decide.

I did this test, and found the cylinders dropped less than 1/16" over 24 hours. That proves the Fit Rite Hydraulics are rock solid. The weak link is the tractor's control valves. I'll start a thread in the Hydraulics section asking questions about that.

 

[MtnViewRanch]

I did this test, and found the cylinders dropped less than 1/16" over 24 hours. That proves the Fit Rite Hydraulics are rock solid. The weak link is the tractor's control valves. I'll start a thread in the Hydraulics section asking questions about that.

I just finished a test with my own cylinders on my 3215, 3 months with the same results that you had, less than 1/16" movement.

 

[dfkrug]

...working in the utility field all aerial units use check valves.

So, when power fails, how do you lower the aerial unit?

This is what Genie uses.