Question about hydraulic top link choices

btulloh · August 29, 2021, 08:05:07 PM

A couple weeks ago I bought a new Kubota MX5400 HST with cab along with a grapple. I had two sets of dual acting remotes installed on the rear. I'm getting ready to add a hydraulic top link and I'm wondering about an option I see for these. It can be just a regular dual port cylinder OR you can get some additional plumbing on top - a double pilot operated check valve between the ports. This is supposed to prevent drift, but I'm using a regular spool for double acting remotes, not a center detent and no float.

I'm not sure if I need or even want the check valve?

Hydraulic plumbing is not my strong suit so input would be helpful.

Thanks.

Southside · August 29, 2021, 08:10:04 PM

You want the check valve, it will require pressure from your remote to allow the cylinder to move, so it becomes just as reliable as a regular top link.

Otherwise if you are using something with a good draft and you encounter a hard spot all the back pressure is against the valve spool, and they will give.

The check is pretty standard on industrial loaders and such for drift and broken hose protection. Pricy, but worth it.

Patrick NC · August 29, 2021, 08:15:07 PM

Quote from: Southside on August 29, 2021, 08:10:04 PM
You want the check valve, it will require pressure from your remote to allow the cylinder to move, so it becomes just as reliable as a regular top link.

Otherwise if you are using something with a good draft and you encounter a hard spot all the back pressure is against the valve spool, and they will give.

The check is pretty standard on industrial loaders and such for drift and broken hose protection. Pricy, but worth it.

X2

btulloh · August 29, 2021, 08:44:01 PM

Well that's a definitive answer. Thanks guys.

Lot of choices out there for top links and no problem finding ones with the check valve. Just need to figure out a good choice and the correct hoses and fittings. I thought this was going to be a simple thing, but it's got me scratching my head about cylinder sources and correct fittings and such.

I was thinking this would be a good way to get a little acquainted with the plumbing, but I'm tempted to just tell the dealer to figure it out for me. That would be easy but pricey and I wouldn't know anything more about applied hydraulics than I do now.

FWIW, two sets of couplers came along with the tractor, so I'm just dealing with threaded hoses to get this done. Probably some adapters, rt angle fittings, etc. amazing how confusing this can be to a rookie.

Southside · August 29, 2021, 10:18:14 PM

There should not be any extra plumbing on the tractor side of the equation. The check valve is usually just a steel block on the side of the cylinder and it will have a relief valve in the block, your hose just goes from the tractor remote and into the block rather than straight into the cylinder.

Post pictures of anything you have questions on. Old Dominion Hydraulics in Ashland is my go to when it comes to cylinders, pumps, valves, etc. Jason is old school and very fair on pricing.

btulloh · August 29, 2021, 11:18:22 PM

That sounds like a good place to get acquainted with. I can get up there in about a half hour, and usually I have other stops to make in Ashland anyway.

I do realize that it's just the matter of two hoses with the correct fittings on each end, but that leaves a lot of variables. I was thinking about just ordering but probably a lot better to give them the couplers and cylinder and the hose length and get the right stuff the first time.

Or are you suggesting that they can make up the ram if I give them the ends, the length and stroke, etc. and have the make up the cylinder from scratch? There are quite a few suppliers that offer that service or off the rack cylinders already fabbed up. My link is nothing unusual lengthwise.

Southside · August 29, 2021, 11:49:06 PM

My guess is you have "Pioneer" female remotes on the tractor. All you need to do is buy a hydraulic top link, Cat 2 given the tractor size, then get a pair of hoses fabbed up with 1/2" male pipe fittings on the tractor end, and whatever is on the piston end, probably JIC. Two male "Pioneer" fittings thread onto the tractor side of the hoses and it's plug and play.

I can get you pictures tomorrow. There is a hose shop right next door to Old Dominion. TSC should have the Pioneer quick connects.

btulloh · August 30, 2021, 07:31:35 AM

Don't worry about the picture. You've got plenty to do besides pictures.

I guess I'm trying to make this more complicated than it is.

Yeah, it's cat 2 and pioneer couplers. I already have the couplers. NAPA is only five miles from me and they can makes the hoses.

TSC has top links, but not in stock. Agrisupply too, and other vendors. I guess any of those will be fine as long as I get cat 2 and the same length as my top link.

Thanks for the replies.

John Mc · August 30, 2021, 02:08:45 PM

As someone who cheaped out and went without the double piloted check valve on my hydraulic toplink, I can say that you definitely want the check valves.

One of these days, I'll get around to replacing mine.

mike_belben · August 30, 2021, 03:54:53 PM

Quote from: btulloh on August 30, 2021, 07:31:35 AM
I guess I'm trying to make this more complicated than it is.

yes, but thats natural to do in uncharted waters. soon in hindsight youll see it was easy. get a checkvalved toplink in your hands for cat 2. then go to the ag shop and make it connect to the remotes, youll be in business.

Dave Shepard · August 30, 2021, 04:29:30 PM

My factory Kubota top-n-tilt top link is just a double acting cylinder. Never had a problem using the winch, 7' field mower, two bottom plow, box blade, etc.

btulloh · August 30, 2021, 08:19:54 PM

Quote from: mike_belben on August 30, 2021, 03:54:53 PM
Quote from: btulloh on August 30, 2021, 07:31:35 AM
I guess I'm trying to make this more complicated than it is.
yes, but thats natural to do in uncharted waters. soon in hindsight youll see it was easy. get a checkvalved toplink in your hands for cat 2. then go to the ag shop and make it connect to the remotes, youll be in business.

Yep, that's the way it usually works. Kinda figured it was time to get over the hump instead of just letting the dealer figure it all out for a small phenomenal fee.
Looks like i can get the top link i need and the right hoses at tsc. Not in stock, but seems to be available in short order. Should be around $350 or so for everything.

Nathan4104 · August 30, 2021, 09:52:33 PM

Double check the tractor end top link 'pin' size. My M7060 is cat 1 on the tractor side and cat 2 on the implement side (factory manual top link).
I don't have a check valve on my Hyd top link cylinder. I can't say I notice any drift but the other comments about valve protection make sense. Make sure you get one with the biggest rod diameter you can find!

mike_belben · August 30, 2021, 09:58:48 PM

...and be VERY CAUTIOUS testing the ranges of homemade attachments. Ive bent 2 toplinks that way on stuff ive built and not maxxed out to check clearance.

Dave Shepard · August 30, 2021, 09:59:50 PM

Valves will be protected by the tractor's relief valve.

mike_belben · August 30, 2021, 10:15:53 PM

The check valves in the live toplink just block fluid from exiting a loaded cylinder if a hose blows with a load on it. You need pressure on the B port to unseat the check thats keeping fluid in the A port side. It cant just drain out by gravity.

Relief valve in the spool is not related at all. Thats in the pump and tank circuit and only come into play when you have lever actuated to block the tank path abd connect the pump to the work path.

These checks are in the work circuit. Soon as you let go of a spool handle the work circuit and pump circuit are disconnected by the spool blocking the connection in the valve block. Being open center, any pressure in the pump line is vented to tank again as normal.

Dave Shepard · August 30, 2021, 10:29:08 PM

I'll have to check my valve, but I thought there was a relief in the block. If so, it would be exclusive to my situation.

btulloh · August 30, 2021, 10:45:16 PM

Quote from: Nathan4104 on August 30, 2021, 09:52:33 PM
Double check the tractor end top link 'pin' size. My M7060 is cat 1 on the tractor side and cat 2 on the implement side (factory manual top link).
I don't have a check valve on my Hyd top link cylinder. I can't say I notice any drift but the other comments about valve protection make sense. Make sure you get one with the biggest rod diameter you can find!

Same with this tractor. Cat 1 at the tractor end. I think there's enough clearance in the bracket to use a bushing with the cat 2 ball end on this particular cylinder. I need to do some careful measuring to make sure though. That's the one potential snag in this plan. That cat 1 pin at the tractor end seems like a Kubota signature move. Seems like an odd thing to do except to make you hostage to their parts department.

Southside · August 30, 2021, 11:37:27 PM

Naa LS does it too. A buddy has a 55 HP can LS that was the same way. About two minutes with an angle grinder and some blue paint and all was well.

Get into the big stuff and you have Cat 3 narrow and Cat 3 wide, never fails I have the wrong quick hitch on.

btulloh · August 31, 2021, 09:07:52 AM

Angle grinder always comes in handy in these situations. I just need to make sure I'm in the two minute category and not the fifteen minute category. Plus these cylinders are black, so matching paint won't be an issue.

Gotta recheck my stroke and length specs too. There are two AMA cylinders that can work - a two inch with 1 3/16 rod or a two and a half with the same rod. For fifty bucks difference it seems like bigger is better.

Mike, I don't know the technical term for the Kubota reliefs, but they do what you want when you exceed the weight capacity. I've had lots of practice with my old l3250 trying to pick up something too heavy and the bypass kicks in to save the day.

Crusarius · August 31, 2021, 09:38:18 AM

btulloh, I have been toying with the same hydraulic toplink setup for my box blade. When you figure it out can you post what you end up with?

btulloh · August 31, 2021, 10:15:51 AM

Will do. If you do a lot of box blade work, the hydro would be a game changer.

I'll post the details when they're worked out, but you'll need to check the geometry on your rig and make choices accordingly. It's simply(? Ha!) a matter of matching the stroke and length to your current top link. And the correct category hitch. And the correct couplers for your rear remotes.

Most tractors use pioneer type couplers on the rear remotes (unless you have a green tractor.

The tricky part with the Kubota M series is that they have cat 2 3pt hitch but the tractor end of the top link uses a 3/4 pin, which is the cat 1 spec.

mike_belben · August 31, 2021, 10:17:23 AM

hydraulics is a big world and im just a little belben so its very possible that there are locking cylinders that also have overload relief incoorporated into the load check block, it wouldnt be hard to do. just a cartridge relief inserted into a common passage between the A and B ports in the block should do it. i have only experience putting the relief in the pumping side of the circuit.

Crusarius · August 31, 2021, 10:43:59 AM

I was just going to buy any old ram cause I had no idea there was such a thing so thanks for the info.

I definitely do alot of box blade work. biggest reason I want the hydraulic top link. I have a Kubota L2800. so its a cute little guy but work good for what I use it for.