Hydraulic questions

[568152]

Now member here. Bought a used Kubota 2020 dozer/snow blade & frame for the Kubota B6200 HST D 4WD I bought & started refurbishing only a few months ago. There are no implements attached at the moment. Where do I shop for a two lever front blade control system so I can hook up the hydraulics for plowing snow? If I rotate the valve in front of the bake pedals to open the hydraulics for the front blade, will the hydraulics for the 3 point hitch still function? Any response will be greatly appreciated.

 

[TheOldHokie]

Now member here. Bought a used Kubota 2020 dozer/snow blade & frame for the Kubota B6200 HST D 4WD I bought & started refurbishing only a few months ago. There are no implements attached at the moment. Where do I shop for a two lever front blade control system so I can hook up the hydraulics for plowing snow? If I rotate the valve in front of the bake pedals to open the hydraulics for the front blade, will the hydraulics for the 3 point hitch still function? Any response will be greatly appreciated.

All you need is an inexpensive ($150) two spool valve with power beyond port. You connect it to the hydraulic outlet block as per the manual and run the tank return to the transmission filler. Your 3pt will function just as before. Here is one on a B7200DT. Just happens to be for the loader but it would work for a snowplow just as well.

Dan

 

[568152]

All you need is an inexpensive ($150) two spool valve with power beyond port. You connect it to the hydraulic outlet block as per the manual and run the tank return to the transmission filler. Your 3pt will function just as before. Here is one on a B7200DT. Just happens to be for the loader but it would work for a snowplow just as well.

Dan

Thank you Dan for your helpful info. Obviously I'm not experienced in tractor hydraulics. I will be very happy if both the plow & the 3 point hitch can be operated without having to switch valve in front of the brake pedals back & forth. When I said "two lever front blade control" I assumed that would work for the plow, but the plow has three hydraulic cylinders, one for lift & one each for left & right angles. Was I correct that a two lever control ( or two spool valve with power beyond port?) will work for that? Further, will it be possible to also allow the plow system to "float". If so does that require a different control system?

 

[TheOldHokie]

Thank you Dan for your helpful info. Obviously I'm not experienced in tractor hydraulics. I will be very happy if both the plow & the 3 point hitch can be operated without having to switch valve in front of the brake pedals back & forth. When I said "two lever front blade control" I assumed that would work for the plow, but the plow has three hydraulic cylinders, one for lift & one each for left & right angles. Was I correct that a two lever control ( or two spool valve with power beyond port?) will work for that? Further, will it be possible to also allow the plow system to "float". If so does that require a different control system?

Inexperienced or not you are asking very good questions:

1) Let's start with the valve in front of the brake pedals. It is a 4 way diverter. When the lever points to the back of the tractor the flow goes straight through to the three point hitch. When it points out to the right the entire flow is diverted to the port on the side of the valve. It should never point to the right unless an implement is connected to it.

2) Now about the implement control valve. You plumb it into the diverter valve with two hoses and the ports on the side of the diverter. The OUT port on the diverter (one closest to the pump) gets connected to the IN port on your implement valve. The power beyond port on the implement valve is then connected to the IN port on the diverter valve (one towards the rear of the tractor. Then and only then you move the lever to the right. Now all of the flow coming from the pump goes out the side of the diverter, through the center of that valve, and back to the diverter valve where it continues on to the 3pt. Both the 3pt and the implement valve are hot" and can be used without ever touching the diverter again.

3) Next up - the implement cylinders. The snow plow has 3 cylinders - one for lift and two for angling the blade. Lets start with the angling cylinders. They are almost surely single acting but you should verify that. Single acting cylinders only have one port for connecting a hose. Assuming they are in fact single acting when one rod extends to angle the blade it pushes the rod on the other one in. You can control both cylinders with one double acting spool on your control valve. One work port on the valve goes to the right cylinder and the other work port goes to the other cylinder. When you move the lever one direction it sends oil to the associated cylinder which extends and pushes the oil in the other cylinder back into the other work port on the valve. and vice versa. The lift cylinder is the biggest unknow - it could be single or double acting depending on the design of the blade. If it has one hose connectiion it is single acting and if it has two it is double acting. If it is double acting it is capable of down pressure and you control it with one double acting spool with float. If it is single acting it is not capable of generating down pressure and you do not need float. You can use a single acting spool (hard to find that combination) or a double acting spool with the unused work port connected to the tank return.

4) Last but not least is the implement tank return. The return port on you power beyond valve is used to return the out flow from the cylinders to the hydraulic reservoir.. That flow needs to go straight to the tank and on some (all??) Bx200 tractors Kubota supplied a hose fitting for the hydraulic filler for just that purpose - part number 70050-01615 ($54). I know that is correct for a B7200DT but may or may not be correct for a B6200HST

Dan

 

[568152]

Inexperienced or not you are asking very good questions:

1) Let's start with the valve in front of the brake pedals. It is a 4 way diverter. When the lever points to the back of the tractor the flow goes straight through to the three point hitch. When it points out to the right the entire flow is diverted to the port on the side of the valve. It should never point to the right unless an implement is connected to it.

2) Now about the implement control valve. You plumb it into the diverter valve with two hoses and the ports on the side of the diverter. The OUT port on the diverter (one closest to the pump) gets connected to the IN port on your implement valve. The power beyond port on the implement valve is then connected to the IN port on the diverter valve (one towards the rear of the tractor. Then and only then you move the lever to the right. Now all of the flow coming from the pump goes out the side of the diverter, through the center of that valve, and back to the diverter valve where it continues on to the 3pt. Both the 3pt and the implement valve are hot" and can be used without ever touching the diverter again.

3) Next up - the implement cylinders. The snow plow has 3 cylinders - one for lift and two for angling the blade. Lets start with the angling cylinders. They are almost surely single acting but you should verify that. Single acting cylinders only have one port for connecting a hose. Assuming they are in fact single acting when one rod extends to angle the blade it pushes the rod on the other one in. You can control both cylinders with one double acting spool on your control valve. One work port on the valve goes to the right cylinder and the other work port goes to the other cylinder. When you move the lever one direction it sends oil to the associated cylinder which extends and pushes the oil in the other cylinder back into the other work port on the valve. and vice versa. The lift cylinder is the biggest unknow - it could be single or double acting depending on the design of the blade. If it has one hose connectiion it is single acting and if it has two it is double acting. If it is double acting it is capable of down pressure and you control it with one double acting spool with float. If it is single acting it is not capable of generating down pressure and you do not need float. You can use a single acting spool (hard to find that combination) or a double acting spool with the unused work port connected to the tank return.

4) Last but not least is the implement tank return. The return port on you power beyond valve is used to return the out flow from the cylinders to the hydraulic reservoir.. That flow needs to go straight to the tank and on some (all??) Bx200 tractors Kubota supplied a hose fitting for the hydraulic filler for just that purpose - part number 70050-01615 ($54). I know that is correct for a B7200DT but may or may not be correct for a B6200HST

Dan

Thanks again Dan: Your excellent description is understood, even for a newbie like me. And thanks too for the photos in your previous reply.

 

[TheOldHokie]

Thanks again Dan: Your excellent description is understood, even for a newbie like me. And thanks too for the photos in your previous reply.

You are more than welcome. I am not endorsing any product but here is one low cost candidate for your control valve. You would need the optional power beyond conversion sleeve. Its also available with float on one spool if your lift cylinder is double acting.

Monoblock Hydraulic Directional Control Valve, 2 Spool, 11 GPM

FREE SHIPPING Monoblock Hydraulic Directional Control Valve, 2 Spool, 11 GPM

summit-hydraulics.com

I will aslo add that if it were me I would opt for one of the joystick models with float on one spool. Its a better way to control the plow and even if you don't need float now you will likely find a time when you do.

Dan

 

[GreensvilleJay]

for snowplowing , you'll use 'float' 99.44% of the time. It allows the blade to follow the contour of the road.