Pump or no pump for my BH80-X

[azhfl56]

Looks like the PTO hp requirements are 20-45. 30hp gross, net somewhere around 28, if you have hydro, probably looking around 22-25hp. So it looks like you will be on the low end, but still manageable. I would suggest you get the pump and make sure you get the sub-frame. What price did you wind up getting?

Regards,

Bryan

 

[dfkrug]

Check the HP requirments for the BH-80x, no offense intended here, but the 3030, may be on the small side for the BH-80x.

The hp requirements stated by manufacturers is a roundabout way of
telling users of WEIGHT requirements, IMO. The 2 ARE related, but not
for all machines. I think, from experience, that the BH-70X makes
more sense for a light-weight unit like the B-series Kubs. I think the
BH-80x will work much better on an L-series or other 3000lb machine.

In terms of hp requirements to run a hyd pump at 2000-2500 psi
at 5-6GPM, only about 15-20hp is needed. 4-6GPM is plenty fast
for the size of cylinders on the Woods hoe (2.75" OD). If a tractor
can not achieve this flow rate, then a PTO pump is indicated. Newer
Japanese CUTs don't have a problem achieving this rate with tractor
hydraulics.

 

[VAMountains]

I wonder, though, if the tractor is stopped, and you're not steering, if it would still take up 3.9 gpm?

Very good question. If you do a search for BH80-X, you'll find other TBNers with the BH who say the B3030 pump is more than adequate to run the hoe. Can you purchase and install the pump later if the tractor pump turns out to be insufficient?

 

[dfkrug]

I have a b7800 with woods 7500 backhoe driven from the tractor hydraulics. I am not happy with the way it works.
I can not perform simultaneous operations with the backhoe controls unless I carefully very very carefully feather the controls. Now I don't know if this is caused by pump capacity, power beyond or if it is just the way it works.
I was told the Kubota hoes all come with a seperate pump.
I think I only saved a coulpe of hundred dollars.

You do not have to feather the controls to get simultaneous hyd circuit
operation. Fluid will always go to the cylinder doing the least work. All
I can say is practice, practice, practice. That said, different makes of
valves feather easier than others, in my experience. There are different
"land" areas on the spools, resulting in longer transitions between cut-off
and flow. My Prince stack valves (CADDigger 728) feathered better than
my Bulgarian-made Prairie Dog valves, but both allowed productive
simultaneous cylinder operations.

PTO pumps add at least $500 to the cost of a hoe and are sold mostly
to bandaid older tractors with low-flow hyd pumps and/or so the
dealer or user does not have to figure out how to plumb remote
hydraulics to their tractor.

 

[dfkrug]

Actually, for the B and L series tractors Kubota uses two pumps, one for the implement hydraulics and one for the power steering hydraulics. Neither's flow can be mixed or combined with the other. For marketing purposes they sometimes add the two gpm's together to get a higher number since the competition is doing the same.

Yes, marketing purposes, for the most part.

Happily, even the budget L-series tractors (LXX00) have moved toward
2 pumps. The older budget Ls, like my 99 L2500, had only one pump
for PS and 3PH/implements.

 

[dfkrug]

My local dealer suggests the pump. He says 95% of his customers get it. (I forgot to ask him whether that was customers in general or specifically B3030 customers). He says it will save heating of the tractors hydraulic oil and will increase the life of the tractor.

Well, 95% of his customers may buy it if he pushes it on them. Especially
if they are newbies. It sure makes the dealer's job easier if he does
not have to help you get remotes put on your CUT. A PTO pump, like
a 3-pt hitch, will go on any tractor.

As for heating the hyd oil, yes any implement will do that. Your tractor's
hyd sysem has a very large capacity and an oil cooler if it has HST. This
is better for long term life of your hoe. Note that serious TLBs, including
the Kub contractor series (B21, L39) don't use PTO pumps (or 3-pt hoe
connections).

 

[rswyan]

I can not perform simultaneous operations with the backhoe controls unless I carefully very very carefully feather the controls. Now I don't know if this is caused by pump capacity, power beyond or if it is just the way it works. I was told the Kubota hoes all come with a seperate pump.

I have a Kubota BL4690B hoe on our B2910 with a separate pump. And I'm not happy either - same deal on having to feather controls very, very carefully to be able to get simultaneous operations. It's less of a problem the faster you run the engine. But I don't feel that I should have to run the engine at full PTO speed to have it operate closer to what I consider "correct".

The boom/swing circuits operate way too fast (even at low rpms) and the dipperstick/bucket ops are slower than they should be (at least from my perspective.) All of this might stem from the fact that Kubota uses an Eaton 20 gpm PTO pump that is designed to be run at 3600 rpm to achieve it's rated flow, if I recall correctly. Running it at 540 produces about 5 gpm.

Having used a Kubota KX-91 excavator there is simply no comparision - the mini-ex has sufficient flow and the hydraulic circuits all seem to be the right speed at almost any engine speed.

Just poor design in my opinion.

 

[MessickFarmEqu]

Having used a Kubota KX-91 excavator there is simply no comparision - the mini-ex has sufficient flow and the hydraulic circuits all seem to be the right speed at almost any engine speed.

Just poor design in my opinion.

The KX's are this way becaues the stick operates with a very complex set of pilot valves and electronic sensors. A KX-91 costs also costs near $40,000. Any backhoe that is not driven by two seperate pumps is going to operate like this. Its simple, the fluid just goes to the cylinder of least resistance. If you want the efficency of being able to stroke multipe functions without interaction from the other stick the only way to get there is with multiple pumps.


We have mounted 4-5 BX80X's on B3030's. It is a big hoe for that tractor, thats no exageration. It does fit though and the tractor seems to handle it just fine. The BX70X is a bit of a sloch for that tractor, as I recall the Kubota BH75 is stonger than the Woods 70X.


On the issue of pump vs no-pump. (which yes, I got the hydraulic flow wrong in my haste). All the additional flow gives you is more speed - it does nothing for power. How many of you run your backhoes with the engine wide open??? (few to none...) things simply start operating too fast once the machine gets about 1/2-3/4 throttle. Kubota is not selling any PTO pump driven backhoes any more, Nor does New Holland. All plumb off the power beyond circuit.

 

[MadReferee]

Kubota is not selling any PTO pump driven backhoes any more, Nor does New Holland. All plumb off the power beyond circuit.

Interesting. So why then did Kubota downgrade the implement hydraulic pump in the B3030? Seems odd to me. Did NH do the same?

 

[Devildog]

I got the bh75 on the back of my 2630 and you really do not want to operate the hoe with the tractor wide open unless you are very familiar with the bh operation. The tractor hydraulics really power this thing.

On Edit: I would go with the tractor hydraulics. Also less stuff to take off and install when removing bh.