kioti 1200 backhoe hydraulics

[Coyote machine]

My DK-40 se/HST tractor, with Kioti hoe, KB-2485, uses the tractor's hydraulic pump, and is controlled by a detented lever that engages the hoe's hydraulics. If I try to use the FEL while the hoe circuit is engaged I get reduced and slower lift then normal. I mention this because I think you need to find a way to shut off the hoe when not in use, and especially when wanting to use the FEL.

 

[rlpearce]

That is exactly what the splitter is for, and does. When using the backhoe there is no power to the FEL and vice versa.

 

[J_J]

Why are you not using the tractor hyd for the FEL, and the PTO pump for the BH.

Still don't know why the splitter is being used. Again, what kind of splitter are you using.

If the FEL is the first valve in the hyd flow path, it can use all of the fluid the pump produces and leave no fluid for the BH.

If you are trying to use the BH and the FEL in the same circuit, then the first valve will have priority, and if using the BH only it will provide back pressure and affect the FEL valve when you try to use it.

If the BH is only using the PTO pump, it will have no effect on the FEL hyd.

This kind of splitter will provide equal flow to two circuits.

3/4" NPT 16-30 GPM DIVIDER VALVE

This is a priority flow divider and will keep the priority flow the same. The remainder of th eflow will go to Excess flow.

6/30 GPM PRINCE PRIORITY FLOW DIVIDER W/RELIEF

 

[rlpearce]

The tractor has no hydraulics except for the PTO pump. At least, none that operate the FEL. I'm not sure what operates the 3 point hitch, it operates independently of the FEL or the backhoe. The splitter is used, I believe, because if two sets of control valves are on the same circuit, in parallel, when you attempt to apply pressure at one set, the fluid has a path through the other set with no resistance. So this splitter applies pressure to one set or the other, not both at the same time. The FEL and backhoe both would not work when I had them connected in parallel. After I put in the splitter, the backhoe worked fine on it's own circuit with the smaller pump. What I don't understand is why it doesn't work with the larger pump, even with a pressure relief valve to dump excess pressure back to the tank.

 

[J_J]

If you use the right splitter, you will have two individual circuits, and can operate two valves at the same time.

For instance, your tractor has a 10 GPM flow, then each hyd circuit will get 5 GPM.

Again, please post the name and model number of the splitter you are using.

Did you understand how the splitters worked in my above post.

Are you using a splitter of a selector valve like this?

3/8" NPT 20 GPM PRINCE SELECTOR VALVE.

If the FEL valve has a PB port why is it not feeding the BH?

 

[rlpearce]

I think the splitter is a Prince SS, with the standard spool
Prince Hydraulics > Products > Hydraulic Valves > Selector > Model SS
I understand how the other splitters work, that is not how this one works.
I don't know if my FEL valve has a PB port or not. (This is an OLD tractor, BTW)
I'll look into that. Also, really don't mean to be beating a dead horse here, but the FEL and backhoe each have a separate return line that goes through a filter and into the tank, so when I select the backhoe circuit it certainly seems that is should not be loading the engine when all valves are in neutral. I don't mind having the manual splitter, and not being able to use the FEL and backhoe both at once, as I couldn't anyway. If there was physically room to do it, I'd install a PTO extension and use both pumps, but there isn't quite enough room.

 

[J_J]

That valve from Prince is a selector valve, not a splitter.

It will provide a flow path to two circuits, one at a time.

If the PTO pump is feeding that valve and you have the BH selected, you should get the full flow and pressure developed by the pump and BH.

If the FEL is selected, then the FEL should get the full flow and pressure developed by the pump and FEL cylinders. Your FEL PB port should be plugged so all flow exits the OUT port.

You might check those filters and see if they are free and clear and not making back pressure .

If the PTO pump is made by Prince, the max psi is only 2250 psi.

How large a PTO pump are you trying to run with your engine?

If the BH loads the pump in neutral, things are not plumbed correctly.

Can you draw out your flow path?

 

[J_J]

Hydraulics:
Capacity: 8 gal [30.3 L]
Pressure: 2800 psi [193.1 bar]
Pump flow: 3.5 gpm [13.2 lpm]

You tractor has enough hyd power 2800 psi to operate a FEL, and has more pressure than the PTO pump 2250 psi.

Tractor hyd might be slow but should lift more that when using the PTO pump.

You should have more power using tractor hyd with the BH, although slower.

What is the GPM on the PTO pump and what rpm is it turning?

 

[rlpearce]

I understand that I could power the FEL and/or the BH with the tractor hydraulics, but I'd rather not do that. Firstly, if I understand correctly, I cannot use the 3 pt. at the same time as FEL or BH if I do this. Also, as you say, they would operate very slowly. I cannot answer your question regarding the GPM of the PTO pump, I don't have that information, and I cannot read make, model, etc. on it. All I can tell you is that it powers the FEL nicely, and that it apparently grossly overpowers the BH. My installation of an adjustable pressure relief valve did not solve the problem, so is it possible that what is needed is a flow control valve instead? One that dumps excess flow back to the tank? Perhaps the BH cannot handle the flow of this pump but it needs the pressure that it or the smaller pump that came with BH provides? Since the BH loads the engine with the valves in neutral, it only makes sense to me that the BH system is too small and restricted to handle the flow from this larger pump. If this is the case, would an adjustable flow control pump such as is used to control hydraulic motors work?

 

[rlpearce]

When I got the BH it had a filter on the return line. My tractor did not. Figuring this was a good time to get one on the tractor I moved the one from the BH to the tractor, since I was no longer using the BH tank anyway. Point of all this is, I just got to wondering if the filter is plugged or is the wrong one to handle the pump I'm using. It should just open an internal bypass if flow exceeds filter capacity but I wonder?