backhoe set up question

[A Bruce]

Hi,
I just bought a Jinma HW 03 back hoe.
It was installed on a Jinma 254 with a separate pump a CBN E 310 rated at 10ml/r and ran at 2000 rpm. I convert this to 5.25 gpm.
I am installing it on my Kubota L 295 dt which does not have a provision to run the 2000 rpm pump.
My Kubota which is at least 40 years old was supplied with two pumps , the factory integral pump, which just runs the three point and a power steering ram, and a Webster pump hooked to the front of the crankshaft. The pump was installed with a KMW loader made in Fort Erie Ontario. The pump has no identifying marks and I have never been able to find out anything about it. it has about a 12 gallon tank . The hydraulics on the loader are strong, almost too strong.

My choices are
1) buy a Prince style pump that goes direct on the pto. I would need a 3.5 inch extension shaft , there are two versions available locally 20.7 gpm, and 6.8 gpm Price is in the 700.00 cdn with parts
2) install a detent kit on my BLB 40 series directional valve on my loader and use my rear hydraulic coupling, removing the hydraulic tank from the backhoe. Price is below 100.00 cdn for parts
3) install a power beyond line to the BLB 40 and another set of disconnects on the rear. Again powering the hoe from the loader pump and removing the backhoe tank from the circuit. Price is below 150.00 cdn for parts

The back hoe is small and meant to replace me running a shovel, we are not going into the excavation business. I do not want to spend more than I have to, but I do not want to do it wrong either. I have limited experience with power beyond or running thru a valve block with a detent kit. I assume I loose some volume and gain some heat. I also am guessing the Webster pump is between 6-8 gpm based on guesses from more experienced people. Note they are guesses.

Thoughts , experiences, suggestions would be appreciated.
thanks

 

[oldnslo]

If you know the size of your loader lift cylinders you can measure the time to extend a given distance and then calculate the pump flow. This would give a reasonably accurate flow rate from the webster pump.

formula is flow rate = cylinder velocity times cylinder area

In the USA I use:
cylinder velocity in inches per second
area in square inches
flow rate in GPM

simplified it is GPM = (Velocity times area) divided 3.85

3.85 is derived by dividing 231 by 60 which cubic inches in a gallon by seconds in a minute

Does the existing FEL valve have power beyond option or would have to use one of the loader functions as supply for the back hoe?

Not familiar with the L295 but can you tap into the flow for the three point and use that to run the back hoe?

FYI: Webster gear pumps was bought and sold a few times so getting information on them is difficult.

 

[A Bruce]

Thanks for the formula, I will do the math, The Valve I have is a four circuit valve, with the power beyond option. If I change to a detent on one of the control valves I dont have to add thwo hoses and quick connects. If I use the power beyond I would need to run two more hoses and add a set of disconnects. My understanding is if I use the power beyond I need to connect the supply to the return when I do not have the backhoe hooked up.
Thank you for the reply
Bruce

 

[Everhard]

Regarding setup given how you described your situation personally I'd go with power beyond option. This will allow you to still use the loader - useful at times for repositioning the tractor and it's a cleaner setup. Also given you won't need the hydraulic tank that's a decent weight savings off the back of the tractor.

E.

 

[A Bruce]

Regarding setup given how you described your situation personally I'd go with power beyond option. This will allow you to still use the loader - useful at times for repositioning the tractor and it's a cleaner setup. Also given you won't need the hydraulic tank that's a decent weight savings off the back of the tractor.

E.

Thank you for your thoughts. The weight savings was not something I had thought of but is an excellent consideration. I appreciate it.