Hydraulic top link issues

[94BULLITT]

I haven't tried the Kubota cylinder on the Ford. But I did try the Ford cylinder on the Kubota. Had the same "air" problem. I installed a restrictor on both cylinders and tried them again on the Kubota. Problem seemed to be solved. Weather hasn't allowed me to try them for more than a couple strokes.

Always open for ideas Pete!!!!

If Kubota puts restrictors in their cylinders, and restrictors fixed your problem, why not run the restrictors?

 

[MtnViewRanch]

If Kubota puts restrictors in their cylinders, and restrictors fixed your problem, why not run the restrictors?

By chance, do you know the size of the orifice that Kubota uses? Just curious.

 

[94BULLITT]

By chance, do you know the size of the orifice that Kubota uses? Just curious.

It is pretty big. I'll pull a hose sometime and check.

 

[MtnViewRanch]

Sounds good, thanks.

 

[olPete]

I haven't tried the Kubota cylinder on the Ford. But I did try the Ford cylinder on the Kubota. Had the same "air" problem. I installed a restrictor on both cylinders and tried them again on the Kubota. Problem seemed to be solved. Weather hasn't allowed me to try them for more than a couple strokes.

Always open for ideas Pete!!!!

Sorry for late reply. Must say LD1s typo stopped me..

And today I've been mowing more grass. Had a bit of trouble with the mower (broke some studs off in the gearbox and had to weld ring spanners to them to get them out) thanks to a jumping power-pole.... didnt get it into reverse in time.
My thought the other evening, was maybe to take the hose off the rod end and keep the port to the top, and bleed the air out the way you would a syringe.. then put it on and repeat with the other end of the cylinder. That way you know for sure that there isn't even a bubble of air left in there. You possibly even do a similar trick with the hoses if you wanted. Could get a little messy but it would guarantee it's air free..
Next question is whether you can adjust the flow on your SCV anywhere. I know you can on most all large tractors, my old girl you have to wind in a little hex bolt on the top and that turns down the flow rate. Could be a cheaper fix than buying a restrictor if it's as easy as that.
Summer's on its way, I promise!!

 

[ovrszd]

If Kubota puts restrictors in their cylinders, and restrictors fixed your problem, why not run the restrictors?

I was unaware that Kubota used restrictors in their kits?? The only reason for them to do this would be owners having problems with their kits like I was having.

I'm with Brian, I'd be very curious to hear what size restrictors they used?

My reason for not liking restrictors is they slow the performance of the cylinder. I spend a lot of time using hydraulic cylinders. That experience has helped me develop my reaction skills. I like hydraulics fast. My Ford has manual flow control settings on the entire hydraulic system and then again at the rear remotes. I run them on the "rabbit" setting all the time.

 

[Kodiak45]

Before I order a flow control valve, I could theoretically test the applicability by trying to get all the air out and then feathering the valve... Right? Hate to spend money on the valve if that's not the real problem.

 

[MtnViewRanch]

Before I order a flow control valve, I could theoretically test the applicability by trying to get all the air out and then feathering the valve... Right? Hate to spend money on the valve if that's not the real problem.

With your implement on the ground, fully cycle your top link 5-10 times. That should get the air out.

Now raise the hitch and see if you can feather your valve to your liking. If that's no big deal, then you should be set. But if the cylinder extends faster than it retracts, then there is a real good chance that a vacuum is getting pulled and you are right back to where you started.

 

[LD1]

Before I order a flow control valve, I could theoretically test the applicability by trying to get all the air out and then feathering the valve... Right? Hate to spend money on the valve if that's not the real problem.

not really.

AS you open the valve slowly (feathering it) the size of the opening allowing fluid to go TO the cylinder is the same size that allows fluid to return. The more you open or close (feather the valve) the more they BOTH open and close in unison.

The flow control slows down ONLY the outgoing fluid, to make sure it isnt leaving faster than it can be replenished by the tractors hydraulics

 

[MtnViewRanch]

not really.

AS you open the valve slowly (feathering it) the size of the opening allowing fluid to go TO the cylinder is the same size that allows fluid to return. The more you open or close (feather the valve) the more they BOTH open and close in unison.

The flow control slows down ONLY the outgoing fluid, to make sure it isnt leaving faster than it can be replenished by the tractors hydraulics

Correct, but with those smaller openings, the pump can keep up, gravity can't pull the unit down quite so fast.

I sell restrictors for both ports. If what you continually say is true, then I would have a lot of pissed off customers, I do not, in fact just the opposite.

In fact, to the best of my knowledge, Richard is the only person that has had a problem with 2 restrictors on the same cylinder and I have sold quite a few units for M8540 & 9540 tractors. I have had 3 customers ever complain about the restrictors, and the complaint was that the units moved to slow. Only Richard has had this vacuum problem.

 

[downsizingnow48]

Would top link cyl diameter have an effect on this problem? I have no idea but could be another variable.

 

[ovrszd]

Would top link cyl diameter have an effect on this problem? I have no idea but could be another variable.

Yes it could. I use rather large cylinders so require more fluid to complete an action.

 

[94BULLITT]

I checked a restrictor in my hydraulic side link. A 1/4'' bit would not fit but a "C" drill bit would which is .242."

 

[94BULLITT]

 

[MtnViewRanch]

No restrictor there, that is simply a std sized port hole for many cylinders. I have had then from 5/32"- 3/8" on different cylinders.

To me for 3" and smaller dia cylinders, you have to be under .090 to really notice any difference at all.

Thank you very much for checking and posting the picture. :thumbsup:

 

[ovrszd]

I agree. No restrictor there.

We're talking about a hole the size of a round tooth pick or smaller.

 

[JRobyn]

^^ Thank you for that little gem up there. Would have never thought of that.

gg

Thanks from me too LD. I disobeyed Brian and went with Kubota OEM valves for my remotes (all three with float). He warned me that some Kubota valves have a leaky history. And your example of the tilt cylinder "shifting" during hours of bushhogging is REAL. It is hard enough to get the bushhog nice and level with manual links. I really don't want to have to explain to the wife (chief bushogger) that she may need to occasionally trim the tilt.

So now I need to figure out what flow control (shutoff) valves to get (at least one) and how/where to mount them. How about a kit, Brian?

 

[MtnViewRanch]

Thanks from me too LD. I disobeyed Brian and went with Kubota OEM valves for my remotes (all three with float). He warned me that some Kubota valves have a leaky history. And your example of the tilt cylinder "shifting" during hours of bushhogging is REAL. It is hard enough to get the bushhog nice and level with manual links. I really don't want to have to explain to the wife (chief bushogger) that she may need to occasionally trim the tilt.

So now I need to figure out what flow control (shutoff) valves to get (at least one) and how/where to mount them. How about a kit, Brian?

Set the side link and un-plug the hose from the rod end of the cylinder.

Done-rock solid.

 

[94BULLITT]

No restrictor there, that is simply a std sized port hole for many cylinders. I have had then from 5/32"- 3/8" on different cylinders.

To me for 3" and smaller dia cylinders, you have to be under .090 to really notice any difference at all.

Thank you very much for checking and posting the picture. :thumbsup:

That is dumb cylinders are made that way. Do they drill the hole in the cylinder small so it can be equipped with different bungs for different size fittings?

 

[MtnViewRanch]

That is dumb cylinders are made that way. Do they drill the hole in the cylinder small so it can be equipped with different bungs for different size fittings?

I don't know why, probably the same reason that the welds get done differently. Just how that particular company happens to do it.