wet lines

steamroller69633

New member

Equipment
L2501
Jan 16, 2022
10
0
1
new jersey
I just bought an L2501 and i already own a tree spade. i would like to plumb auxiliary hydraulic lines to use the spade. my question is , do i split the power beyond line coming from the loader bucket into 2 lines with quick connects that i leave connected when not using the spade, then split them and hook them to the spade feed lines. Or do i just tee the pump fitting and the tank fitting with quick connects that sit all the time and are only used when the spade is used?
any help would be awesome. thank you
 

old and tired

Well-known member

Equipment
L2800 HST; 2005; R4
You can not "T" the high pressure line which is the Power Beyond port. You need to add a valve/spool in series, one after another. So, you need Open Center Valve with Power Beyond.

Open center means that pressure is available to each valve but the ones up stream gets the power first. If you "T" into the high pressure the oil will always take the path of least resistance back to the tank meaning you'll not get pressure where you want it to work. It will take the other route....

I wanted a grapple and top and tilt hydraulics, added 3 spools after the FEL. The power beyond feed the new 3 spools, I ended up using the old power beyond hose to come out of the new spool to power the 3 point hitch.

My grapple has quick connects on the valve/spool, when it's disconnected, the oil just flows through the valve. If it doesn't make sense... let us know and we can try and explain it again.... Hydraulics allow the tractor to work!!!
 
Last edited:

steamroller69633

New member

Equipment
L2501
Jan 16, 2022
10
0
1
new jersey
So the spade is for a bobcat. And is fed from the aux lines. It has its own set of 6 spool valves. I kind of figured it out that i need to plumb this like a backhoe attachment. Im going to remove the power beyond line from the fel. Add a 6” line with a quick connect. Then put the opposing quick connect on the original line. No spade attached =the lines are connected. Spade attached = lines attached to spade spool valves. To complete the power beyond loop at all times.
 

steamroller69633

New member

Equipment
L2501
Jan 16, 2022
10
0
1
new jersey
You can not "T" the high pressure line which is the Power Beyond port. You need to add a valve/spool in series, one after another. So, you need Open Center Valve with Power Beyond.

Open center means that pressure is available to each valve but the ones up stream gets the power first. If you "T" into the high pressure the oil will always take the path of least resistance back to the tank meaning you'll not get pressure where you want it to work. It will take the other route....

I wanted a grapple and top and tilt hydraulics, added 3 spools after the FEL. The power beyond feed the new 3 spools, I ended up using the old power beyond hose to come out of the new spool to power the 3 point hitch.

My grapple has quick connects on the valve/spool, when it's disconnected, the oil just flows through the valve. If it doesn't make sense... let us know and we can try and explain it again.... Hydraulics allow the tractor to work!!!
Oh and i wanted to say. I was never going to tee the power beyond. I was going to tee the pump line and the tank line. Run the pressure through the spade manifold and back to the tank.
 

steamroller69633

New member

Equipment
L2501
Jan 16, 2022
10
0
1
new jersey
I think I follow what you want to do... My guess, is that the tractor's flow (gallons per minute) is going to be way too slow for the skid steer implement. How often do you plan to use this?? Do you know what the spade's required flow is???
Not sure about the flow requirements but its on a super old bobcat that at its best only made 10gpm. Its not duty cycle, it only pushes blades into soil. Then retracts them when setting the root ball. I imagine it will be slow but the pressures are the same on both machines
 

torch

Well-known member

Equipment
B7100HSD, B2789, B2550, B4672, 48" cultivator, homemade FEL and Cab
Jun 10, 2016
2,583
831
113
Muskoka, Ont.
The "correct" way to add an additional hydraulic implement is to re-route the PB outlet from the FEL to the spade inlet, route the spade PB outlet to it's former location and tee the Tank lines together (or run the spade Tank line separately back to the reservoir). That is the only way you should do it if you are going to leave both sets of controls in-circuit.

However, if I understand correctly, the spade controls are mounted to the spade itself and stay with the spade when it is detached? There are two ways I can think of to safely plumb this:

1. Install a diverter valve on the pump line, such that it can feed either the FEL or the spade, but not both. Install a quick-disconnect pair on the line to the spade. Install check valves on both FEL and spade PB ports. Insert a tee fitting in the PB line (after the check valve, of course!) from the FEL and a quick connect pair for the spade in that tee. Install a tee in the tank line, with a quick connect pair for the spade. In operation, the FEL and spade controls could be connected simultaneously, however selection between FEL or spade operation would be mutually exclusive, dependent upon the position of the diverter valve. Engine must be temporarily stopped before operating diverter valve.

2. Alternatively, install quick-connect pairs in both the FEL and spade lines. Completely disconnect the FEL control from the system and connect the spade control in it's place. (Tank line could be tee'd as above) While this has the virtue of simplicity and reduced overall cost, it would be less convenient. I imagine FEL operation would be a key component to placing the tree spade so it would be necessary to swap hoses around several times each time the spade is used. Not a big deal if you need it once a year, PITA if you need it once a week.

All that said, I have to wonder if the tractor has sufficient weight to anchor the tree spade. If the spade has enough weight, can the tractor FEL lift it, even empty? An SSQA adapter to the 3ph might be a better solution. Perhaps incorporating a locking mechanism to the tractor draw bar mount to prevent lifting of the 3ph arms in use.
 

steamroller69633

New member

Equipment
L2501
Jan 16, 2022
10
0
1
new jersey
That makes sense...

So, how big of a root ball do you think the L2501 can lift?
So that is the question. I bought the bobcat and 32” spade combo to move 30-10’tall Leyland Cypress trees. It was a good deal but need work. Engine work and hoses. I fixed everything and last week tried to move a tree. The bobcat wont lift it. Its capacity was 1100 but it is from 1987 so who knows at this point. I wanted to try it on the 2501 before renting a bigger bobcat to do the job.
 

steamroller69633

New member

Equipment
L2501
Jan 16, 2022
10
0
1
new jersey
The "correct" way to add an additional hydraulic implement is to re-route the PB outlet from the FEL to the spade inlet, route the spade PB outlet to it's former location and tee the Tank lines together (or run the spade Tank line separately back to the reservoir). That is the only way you should do it if you are going to leave both sets of controls in-circuit.

However, if I understand correctly, the spade controls are mounted to the spade itself and stay with the spade when it is detached? There are two ways I can think of to safely plumb this:

1. Install a diverter valve on the pump line, such that it can feed either the FEL or the spade, but not both. Install a quick-disconnect pair on the line to the spade. Install check valves on both FEL and spade PB ports. Insert a tee fitting in the PB line (after the check valve, of course!) from the FEL and a quick connect pair for the spade in that tee. Install a tee in the tank line, with a quick connect pair for the spade. In operation, the FEL and spade controls could be connected simultaneously, however selection between FEL or spade operation would be mutually exclusive, dependent upon the position of the diverter valve. Engine must be temporarily stopped before operating diverter valve.

2. Alternatively, install quick-connect pairs in both the FEL and spade lines. Completely disconnect the FEL control from the system and connect the spade control in it's place. (Tank line could be tee'd as above) While this has the virtue of simplicity and reduced overall cost, it would be less convenient. I imagine FEL operation would be a key component to placing the tree spade so it would be necessary to swap hoses around several times each time the spade is used. Not a big deal if you need it once a year, PITA if you need it once a week.

All that said, I have to wonder if the tractor has sufficient weight to anchor the tree spade. If the spade has enough weight, can the tractor FEL lift it, even empty? An SSQA adapter to the 3ph might be a better solution. Perhaps incorporating a locking mechanism to the tractor draw bar mount to prevent lifting of the 3ph arms in use.
Its funny. I was going to message you directly before posting my thread. You seem quite knowledgeable in this arena. My question is this, when installing the backhoe, the Pb hose goes to the backhoe, then back to the block. There are quick connects that attach to the backhoe implement and when not in use they connect back to one another completing the loop. The spade is designed to be run on a 2 line system, feed and return. The spade valves allow oil to flow through when no spool valves are activated. Why can i not hook the spade up the same way as the backhoe (never involving pump hose or tank hose)?
oh and the spade weighs 1000. The tree and ball is probably 3-400. I know its going to max the 2501 or overload it. I just wanted to try it out of self amusement before renting or borrowing a bigger bobcat.
 

torch

Well-known member

Equipment
B7100HSD, B2789, B2550, B4672, 48" cultivator, homemade FEL and Cab
Jun 10, 2016
2,583
831
113
Muskoka, Ont.
Third option: add a PTO powered auxiliary hydraulic pump that stays with the tree spade. Probably the most expensive option, but if the spade sees regular use it has the advantages of increased flow and seamless interoperability with the FEL or 3ph.
 

torch

Well-known member

Equipment
B7100HSD, B2789, B2550, B4672, 48" cultivator, homemade FEL and Cab
Jun 10, 2016
2,583
831
113
Muskoka, Ont.
Its funny. I was going to message you directly before posting my thread. You seem quite knowledgeable in this arena. My question is this, when installing the backhoe, the Pb hose goes to the backhoe, then back to the block. There are quick connects that attach to the backhoe implement and when not in use they connect back to one another completing the loop. The spade is designed to be run on a 2 line system, feed and return. The spade valves allow oil to flow through when no spool valves are activated. Why can i not hook the spade up the same way as the backhoe (never involving pump hose or tank hose)?
oh and the spade weighs 1000. The tree and ball is probably 3-400. I know its going to max the 2501 or overload it. I just wanted to try it out of self amusement before renting or borrowing a bigger bobcat.
Sorry, I missed this before my last comment. (Trying to co-ordinate on-line learning for grandson due to snow day this morning).

If the backhoe is connected to the FEL PB port, then there should be 3 hoses. Failure to provide the 3rd (tank) hose takes the pressure relief valve out of the circuit in the event that the 3ph is operated simultaneously. If, however, the return from the backhoe is actually connected to the hydraulic reservoir directly, such that the 3ph cannot be operated simultaneously, then 2 hoses are fine because the backhoe is effectively the end of the hydraulic circuit.

It is possible to connect the BH just as you described and never have an issue, simply because one is extremely unlikely to attempt operation of the BH and 3PH simultaneously. Without a PB port, the BH relief valve simply dumps to the single outlet (tank) port, which flows through the 3PH open centre to the tank when the 3PH is in neutral. Overpressure is only possible when the 3PH control is directing the flow to the 3PH lift cylinder instead of the tank AND the FEL relief valve is operating (eg: cylinder fully extended or retracted). In that case, the relief valve pressures are compounded and the system can be over-pressurized.

You could simply connect the spade hoses to the BH outlets. IF the BH outlet is actually connected to the tank and by-passes the 3PH, that would be fine. If the BH outlet is connected to the 3PH inlet, then the same over-pressurization of the system is possible if the 3PH is actuated at the same time as the spade is actuated.

At the very least, I would rig some sort of lock-out on the 3PH lever to prevent operation when the BH or spade are hooked up.
 

steamroller69633

New member

Equipment
L2501
Jan 16, 2022
10
0
1
new jersey
Sorry, I missed this before my last comment. (Trying to co-ordinate on-line learning for grandson due to snow day this morning).

If the backhoe is connected to the FEL PB port, then there should be 3 hoses. Failure to provide the 3rd (tank) hose takes the pressure relief valve out of the circuit in the event that the 3ph is operated simultaneously. If, however, the return from the backhoe is actually connected to the hydraulic reservoir directly, such that the 3ph cannot be operated simultaneously, then 2 hoses are fine because the backhoe is effectively the end of the hydraulic circuit.

It is possible to connect the BH just as you described and never have an issue, simply because one is extremely unlikely to attempt operation of the BH and 3PH simultaneously. Without a PB port, the BH relief valve simply dumps to the single outlet (tank) port, which flows through the 3PH open centre to the tank when the 3PH is in neutral. Overpressure is only possible when the 3PH control is directing the flow to the 3PH lift cylinder instead of the tank AND the FEL relief valve is operating (eg: cylinder fully extended or retracted). In that case, the relief valve pressures are compounded and the system can be over-pressurized.

You could simply connect the spade hoses to the BH outlets. IF the BH outlet is actually connected to the tank and by-passes the 3PH, that would be fine. If the BH outlet is connected to the 3PH inlet, then the same over-pressurization of the system is possible if the 3PH is actuated at the same time as the spade is actuated.

At the very least, I would rig some sort of lock-out on the 3PH lever to prevent operation when the BH or spade are hooked up.
Thank you. It would be so infrequently used and only by me, that i think it wouldnt be an issue. I just happened to look at my friends kubota and see the plumbing for the backhoe. It surprised me. Only 2 lines.
 

torch

Well-known member

Equipment
B7100HSD, B2789, B2550, B4672, 48" cultivator, homemade FEL and Cab
Jun 10, 2016
2,583
831
113
Muskoka, Ont.
Thank you. It would be so infrequently used and only by me, that i think it wouldnt be an issue. I just happened to look at my friends kubota and see the plumbing for the backhoe. It surprised me. Only 2 lines.
I did not realize the backhoe installation was on a different machine.

If you installed either a diverter valve or quick-connect pair on the line from the PB out of the FEL, and a tee with a quick-connect outlet in the line to the tank, you would effectively by-pass the 3PH and make the spade the last attachment in the chain instead -- which only requires 2 lines (this assumes the spade control has it's own built-in relief valve).

In fact, Kubota provides this capability on some machines. My B7100 has a diverter valve and outlet after the 3PH control. The lever then controls either supply to the 3ph OR supply to another attachment depending on position of the diverter valve. This would be the preferred connection point if the attachment does not incorporate it's own relief valve, as the 3PH relief is still in-circuit.
 

old and tired

Well-known member

Equipment
L2800 HST; 2005; R4
So, it's your friends backhoe and not yours? I would pay your friend to come over with the backhoe to dig the holes and dig up the trees, slide them into your FEL and do it that way.

Another thing to think about, the tractors are set up at (usually) the lowest setting in PSI range. Several of us have, not only maxed out the scale but have gone over 5% higher. Makes a difference. Have you checked what pressure the Bobcat loader is set at?

You might not be able to lift the spade but you might be able to curl it back enough to drive around. There are threads about moving 1500lbs hay bales...
 

steamroller69633

New member

Equipment
L2501
Jan 16, 2022
10
0
1
new jersey
So, it's your friends backhoe and not yours? I would pay your friend to come over with the backhoe to dig the holes and dig up the trees, slide them into your FEL and do it that way.

Another thing to think about, the tractors are set up at (usually) the lowest setting in PSI range. Several of us have, not only maxed out the scale but have gone over 5% higher. Makes a difference. Have you checked what pressure the Bobcat loader is set at?

You might not be able to lift the spade but you might be able to curl it back enough to drive around. There are threads about moving 1500lbs hay bales...
Bobcat is 2250psi
Are you talking about turning up the pressure on the kubota? Is that by putting shims in the block where the fel lines connect
 

steamroller69633

New member

Equipment
L2501
Jan 16, 2022
10
0
1
new jersey
I did not realize the backhoe installation was on a different machine.

If you installed either a diverter valve or quick-connect pair on the line from the PB out of the FEL, and a tee with a quick-connect outlet in the line to the tank, you would effectively by-pass the 3PH and make the spade the last attachment in the chain instead -- which only requires 2 lines (this assumes the spade control has it's own built-in relief valve).

In fact, Kubota provides this capability on some machines. My B7100 has a diverter valve and outlet after the 3PH control. The lever then controls either supply to the 3ph OR supply to another attachment depending on position of the diverter valve. This would be the preferred connection point if the attachment does not incorporate it's own relief valve, as the 3PH relief is still in-circuit.
I guess the reason why i am struggling to understand you is i dont have a complete understanding of kubotas power beyond setup. The oil goes from the pump , to the fel valve. Then it is sent on through to the power beyond circuit, unless you actuate the fel valve? Then it goes through the cylinder and back to the tank? Or is the tank line just for pressure relief?
 

steamroller69633

New member

Equipment
L2501
Jan 16, 2022
10
0
1
new jersey
I did not realize the backhoe installation was on a different machine.

If you installed either a diverter valve or quick-connect pair on the line from the PB out of the FEL, and a tee with a quick-connect outlet in the line to the tank, you would effectively by-pass the 3PH and make the spade the last attachment in the chain instead -- which only requires 2 lines (this assumes the spade control has it's own built-in relief valve).

In fact, Kubota provides this capability on some machines. My B7100 has a diverter valve and outlet after the 3PH control. The lever then controls either supply to the 3ph OR supply to another attachment depending on position of the diverter valve. This would be the preferred connection point if the attachment does not incorporate it's own relief valve, as the 3PH relief is still in-circuit.
This is what I thought i could do.
 

Attachments

torch

Well-known member

Equipment
B7100HSD, B2789, B2550, B4672, 48" cultivator, homemade FEL and Cab
Jun 10, 2016
2,583
831
113
Muskoka, Ont.
I guess the reason why i am struggling to understand you is i dont have a complete understanding of kubotas power beyond setup. The oil goes from the pump , to the fel valve. Then it is sent on through to the power beyond circuit, unless you actuate the fel valve? Then it goes through the cylinder and back to the tank? Or is the tank line just for pressure relief?
Fluid from the pump goes into the Pump port. If the controls are in neutral, then the Open Center just passes the fluid on to the PB port and from there to the next control in the chain. If that control is also in neutral, then the fluid is passed on to the next in the chain, and so on. If all valves are in neutral, then the fluid is passed by the last valve straight back into the reservoir, and no (well, very little) pressure is developed in the system -- the pump is simply cycling fluid around the system.

With PB: If one of the control spools is activated, then fluid from the Pump port is diverted to the corresponding cylinder, and it moves. That is to say, the upstream spool valve cuts downstream valves out of the circuit -- it is not possible to use the 3PH when the FEL control is actuated.

As it moves, fluid from the opposite end of the cylinder is pushed out, and returns to the reservoir via the Tank port & hose. When the cylinder reaches the end of it's stroke (or capacity is otherwise exceeded) and the pressure rises above the relief valve setting, the relief valve opens and dumps excess fluid back to the reservoir via the Tank port & line, preventing damage like burst lines, cylinder(s) or pump casing.

The critical factor here is that the relief valve responds to the difference between inlet pressure and outlet pressure. So long as the outlet pressure is nearly 0, the relief valve limits upstream pressure to it's setting. More on that in a moment.

Without PB: If open center spool valves are chained in series without PB -- that is, with just the two hoses such that the Tank port from the upstream spool valve is connected to the downstream spool valve Pump port, then when one of the upstream spools is activated, fluid from the Pump port is diverted to the corresponding cylinder, etc. as before. However, the returning fluid and the relief valve discharge are passed through the Tank port to the downstream valve instead of directly to the reservoir. Now, so long as the downstream spool valve(s) are in neutral, things will work as expected since the fluid simply passes through open centres and back into the reservoir -- just as it would if it was passing through a dedicated hose direct to the tank from the upstream valve in a PB system.

The problem arises when both downstream and upstream valves are actuated simultaneously (possible only because the downstream system is supplied by the discharge of the upstream system). Consider the case of simultaneous operation of a FEL upstream and 3PH downstream without the use of PB and the third hose:

Let us say that the system is designed for a maximum pressure of 1800psi and therefore both the FEL and 3PH relief valves are set to 1800psi. The 3PH valve is operated, the Open Centre is closed, the 3PH rises to maximum and the relief valve operates. Pressure between the pump and the relief valve has now risen from 0psi to 1800psi. At the same time, the FEL cylinder hits it's maximum extension. The FEL relief valve sees a pressure difference of 1800psi inlet - 1800psi outlet = 0psi, so it does not open. It will remain closed until the pressure rises to 3600psi inlet - 1800psi outlet = 1800psi. This is called compounding the relief valves. Of course, there's a good chance that something will fail -- catastrophically -- before then!

How likely is the above? It is an example of the perfect storm. If at any time the 3PH control is returned to neutral, the Open Centre of the spool valve will immediately start dumping fluid to the reservoir and system pressure will again be limited to the 1800psi setpoint of the FEL relief valve. There are few if any situations were someone would deliberately operate both controls simultaneously -- especially if the valves are operated by the same hand. But it is a real possibility that one valve might be operated inadvertently and if that happens, the pressures will rise faster than humans can react. The PB port and 3rd hose are there to prevent the possibility of irreversible and expensive damage.

And in case it is not yet obvious, the last set of spool valves do not require a PB port or third hose because all fluid from that point on is going straight back to the reservoir -- it is not possible to compound the final relief valve.

Clear as mud? <lol>
 
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