Dirt Moving Rear hydraulic remote .

[Amvcane]

I’m shocked it took this long before that was brought up.

X2 The laws of physics cannot be broken.

 

[ovrszd]

I've been involved in some very lengthy and technical discussions about this problem. It's hard to discuss without some getting aggravated and insulting. Took me a long time to accept some of the theories.

Here's one. If you unplug the cylinder mid stroke, and put an extending load on it, it's possible for the cylinder to extend without internal cylinder failure.

Here's one. If you unplug the cylinder mid stroke, and put a compression load on it, it's not possible for the cylinder to collapse, even if the internal gland has no O-rings or seals on it.

These theories require thought and discussion to accept.

 

[ovrszd]

Here's what my pea sized brain has stored from this discussion so far.

In normal operation the top link "appears" to have air in it. Moves in and out based on load. Not sure if it is able to fully extend or collapse.

When the top link is uncoupled mid stroke and put in use it still moves in and out based on load. Not sure if it is able to fully extend or collapse.

OP's last comment indicates that the top link displays no control when in use. Completely moves in reaction to load as if it's not coupled to the tractor.

Maybe I've missed something?

 

[ovrszd]

Pleasantly surprised this thread has not gone south.

If the cylinder is fully extended and no air in the system, I don't see how it could retract with hoses plugged even if the cylinder is bypassing internally. I would suggest cycling the cylinder with no weight to eliminate the possibility that it extends faster than the hydraulic pump can fill the cylinder.

My top link has always held pretty well.

When I was trying to find a solution to my problem Brian from Fit-Rite sent me a restrictor. I put in in the cylinder circuit. Purpose being to keep the system from sucking air because of fast extension. It did not help my situation one bit. I finally took it out because I hated how it slowed the use of the cylinder. It would actually make my hydraulics scream against the relief valve because it slowed the flow so much.

 

[npalen]

I am also a member of the "funny top link cylinder club". I guess I'm of the opinion that, if I need to "stiffen" the cylinder, I will raise the 3PT fully then SLOWLY extend the top link cylinder making sure to not introduce any air. May need to do this several times and the results seem to be only a temporary fix. I also have added restrictor fittings.

As ovrszd mentions above, there is a difference with issues depending whether extending and retracting. The issues encountered with top link cylinders and FEL bucket cylinders may have some similarity due to the fact they are normally extended under load.

Industrial hydraulic presses, shears and brakes use what is called a counterbalance valve for several reasons including safety as well as not pulling a vacuum when lowering the ram. They all, or most, extend the cylinders on the downstroke same as a top link cylinder. There is a lot to be said for pilot operated checks on a top link setup especially on the rod end port.

Maybe someone needs to design a top link cylinder that extends rather than retracts under load??????

 

[ovrszd]

Good stuff npalen.

I've often wondered if DPCVs prevent the air problem??? I've not been able to wrap my mind around it enough to come to conclusion.

With DPCV it requires pressure to open the valve and allow the cylinder to move. In theory that would prevent any type of vacuum because the valve would close as soon as the pressure dropped below the prescribed psi setting within the valve.

So maybe they would solve the problem??

 

[ptsg]

Good stuff npalen.

I've often wondered if DPCVs prevent the air problem??? I've not been able to wrap my mind around it enough to come to conclusion.

With DPCV it requires pressure to open the valve and allow the cylinder to move. In theory that would prevent any type of vacuum because the valve would close as soon as the pressure dropped below the prescribed psi setting within the valve.

So maybe they would solve the problem??

Yes it solves that issue. Also it's safer in case of a hose blow up. That's why it's a requirement on top links on some countries.

 

[ovrszd]

Yes it solves that issue. Also it's safer in case of a hose blow up. That's why it's a requirement on top links on some countries.

Good stuff!!! Thanks for that clarity.

I'm now using my Ford with Hydraulic Top Link more now for blading/grading purposes. I may add a DPCV since I know now it solves the problem. I hated to convert it and then still have the same problem. Thanks.

 

[ptsg]

Good stuff!!! Thanks for that clarity.

I'm now using my Ford with Hydraulic Top Link more now for blading/grading purposes. I may add a DPCV since I know now it solves the problem. I hated to convert it and then still have the same problem. Thanks.

The DPCV kits are fairly inexpensive and some hydraulic shops with cut the hard lines for you, once you get them the distance between ports.

 

[ovrszd]

The DPCV kits are fairly inexpensive and some hydraulic shops with cut the hard lines for you, once you get them the distance between ports.

Yep. I think I'll do that. If/when I do I'll post the results on this thread.