The problem of the overly well-endowed hoist:

[TomSeller]

I would not connect a single pipe hydraulic cylinder to a typical tractor hydraulic system if it were me. While filling the cylinder, there is no return to the tank (transmission). You have to remember the fluid is used for the transmission itself. Are you sure there is not a fitting on the other side of the cylinder? A cylinder can be made with hydraulics on one side and let gravity pull it down, but why? Typically when you are pushing fluid into one side, you want it coming back out the other side so you continue fluid flow. Are you switching the hydraulic line on your spool when you drop the trailer bed? Is there an owners manual diagram you can post?

 

[Midniteoyl]

Dont over fill the tranny..

 

[Stonehaller]

With a typical, double acting, rear remote, you will be dead heading the pump when you lower the dump trailer. That is why you heard the tractor strain at the dealer. That will not hurt if you do not take too long to lower it or do it to frequently.

As others said, do not over fill the tractor. Compare the cylinder volume with the amount of oil in the tractor. If the cylinder is 25% or less then you should be fine. If the trailer manual does not give the cylinder volume, then estimate it from measurements of the cylinder. I would not recommend driving or working the tractor much with the dump raised.

 

[aczlan]

It doesn't sound or feel as if it's unhappy when lifting. Interestingly, at the dealer the guy demonstrated the hoist with a 40 hp Mahindra. The Mahindra's engine came under light load both in the lifting and lowering of the box. I asked why. The technician said that it loads the pump to force oil back through it. The Kubota is obviously plumbed differently. The single hose works fine, though I can drop the box with a smash if I'm not careful. There's a dump line (I guess) straight into the transmission.

Its probbaly because the Mahindra puts out more flow than will fit in the hose to the cylinder, so it had to waste some via the pressure relief valve. Your B7510 has a low enough hydraulic flow that it can all flow down the hose.

Aaron Z

 

[Midniteoyl]

With a typical, double acting, rear remote, you will be dead heading the pump when you lower the dump trailer. That is why you heard the tractor strain at the dealer. That will not hurt if you do not take too long to lower it or do it to frequently.

As others said, do not over fill the tractor. Compare the cylinder volume with the amount of oil in the tractor. If the cylinder is 25% or less then you should be fine. If the trailer manual does not give the cylinder volume, then estimate it from measurements of the cylinder. I would not recommend driving or working the tractor much with the dump raised.

Agreed..

 

[Rod in Forfar]

Agreed..

Thanks for the input. I'll proceed cautiously, and not add any extra oil.

Rod

 

[bcp]

Looks like it is a single-action cylinder with the rod being the piston. No oil space on the rod side.

If worried, get a double-acting cylinder of the same specs and plumb a return line.

Bruce

 

[Rod in Forfar]

View attachment 334454

Looks like it is a single-action cylinder with the rod being the piston. No oil space on the rod side.

If worried, get a double-acting cylinder of the same specs and plumb a return line.

Bruce

Bruce:

I thought of that, but unless it will produce an imminent threat to the tractor, I'd like to try the trailer a bit first to see if it can earn itself a place on the farm. If not, down the road it goes. One stopgap solution would be simply to plug the hose into the TAFE 351 when I need to dump it. It holds over 10 gallons.

Rod

 

[oldnslo]

2 1/2" bore x 24" stroke cylinder requires 1/2 gallon to fill it.
3" bore x 24" stroke requires 3/4 gallon
4" bore 24" stroke is 1.31 gallons

I would be concerned with the 4" bore but the 3" and smaller would not concern me to operate.

 

[Rod in Forfar]

2 1/2" bore x 24" stroke cylinder requires 1/2 gallon to fill it.
3" bore x 24" stroke requires 3/4 gallon
4" bore 24" stroke is 1.31 gallons

I would be concerned with the 4" bore but the 3" and smaller would not concern me to operate.

The bore is 2 3/4" and the stroke is 19".

While at full or even half-extension of the cylinder the dipstick is dry; at 1/3 elevation (6" showing silver on the cylinder) the dipstick reads halfway between top and bottom. That still has the bed up 3' above its bunks at the front, which looks to be a useful and safe elevation for firewood, for example. Only momentarily would I need to raise the box higher than that to loosen sand or gravel while spreading.

A more careful look at the apparently fragile metal sides of the trailer suggests that there's no reason not to line the inside with sturdy plywood, perhaps incorporating a gunwale to add shock resistance for when someone drops a piece of scaffold or a block on the edge. My wife discovered while gardening that the trailer can be towed around with the sides down without rattles or damage.

Thanks for the input, Oldnslo,

Rod