Pump or no pump for my BH80-X

[dfkrug]

Kubota is not selling any PTO pump driven backhoes any more, Nor does New Holland.

Yes, interesting.

Now if Kubota only drops their last 3-pt backhoe.... I talked to the
factory rep at the last World AG Expo and I asked him how they
reconcile their policy of voiding the warranty when a user puts a
b/h on the 3PH, with Kubota selling a 3PH hoe. He sheepishly
acknowledged the irony.

As to excavators...they do work very well, with multiple pumps and
proportional control. I have spent a few hours in the saddle and I
will always have that to compare to.....

 

[rswyan]

Neil,

I appreciate the fact that the KX-91 is alot of money ..... it is quite a machine ..... but ....... I'm not convinced that Kubota engineering couldn't come up with a better solution for the performance issues on the BL4690B (and maybe on their other backhoes.)

If I recall correctly from reading the manual there are flow restrictors in some of the circuits - I believe it might be the dipperstick & bucket circuits. The manual makes a big point of how if the valve is disassembled these restrictors must be put back in.

Anyways, if that is the case, it would make sense to me that flow restrictors are really needed in the boom/swing circuits, which when I'm running at 1500 - 1800 rpm are very fast .... almost too fast - not the dipperstick/bucket circuits - which are almost painfully slow at the same rpm.

I would think that some sort of porportional divider valve might solve this problem - and I can't imagine that it would be impossible to engineer something like this that was intergral to the stack valve on the BL4690B. Especially when you consider that standalone flow dividers retail for $100 or less.

In hindsight I think I'd be alot happier if I had taken what I spent on the BL4690B and used it as a downpayment on a mini-ex - they are just so much more capable and productive (Bob Skurka .... I shoulda listened to ya ..... )

After having said the above though, I rather have some sort of backhoe than none at all.

 

[ronjhall]

After having said the above though, I rather have some sort of backhoe than none at all.

I have the same BH as you do. Works well for my projects. Would like some of the newer and more powerful stuff. Mine will get more done than a shovel.

 

[rswyan]

Ron,

I hear ya

I'm in the middle of trenching for some drain lines ........ and with every full or half-full bucket of hard, compacted clay I dug out I thought about how many shovelfuls it would be, how sore my back would be - and gladly rejoiced at how fortunate I am to have it.

 

[BrianW]

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

I am curious. What did they downgrade it from. I noticed the B2630 has a 9.8 gpm pump and the B3030 has a 9.1 gpm pump but I thought this was the same pump run at two different RPMs. The B3030 HP is rated at 2600 RPM and the B2630 is rated at 2800 RPM.

 

[MadReferee]

I am curious. What did they downgrade it from. I noticed the B2630 has a 9.8 gpm pump and the B3030 has a 9.1 gpm pump but I thought this was the same pump run at two different RPMs. The B3030 HP is rated at 2600 RPM and the B2630 is rated at 2800 RPM.

After doing some research I find that the B2630 rates HP and hydraulic flow at 2800 RPM while the B3030 does it at 2600 RPM. The part numbers for the two pumps appear to be the same. I should have done my homework a little better.

The B-series Kubotas have 2 pumps, one for the implements and one for the power steering. The 9.x gpm is the combined output of the two. The B2630 has 4.2 for the PS and 5.6 for implements. The B3030 has 3.9 for PS and 5.2 for implements. The only difference is the RPM at which the numbers are taken.

 

[dfkrug]

The B-series Kubotas have 2 pumps, one for the implements and one for the power steering.

.....and a 3rd pump for the HST, if it has it.....

 

[MadReferee]

.....and a 3rd pump for the HST, if it has it.....

Yea, well, that one is kinda obvious.

 

[DiezNutz]

Without naming names, there's a few ppl in this thread talking out their @ss - get your facts straight before you post clutter to mislead others!

First of all, yes it's a DUAL pump - power steering has it's own circuit and has nothing to do with any of this.

Page 3 of B3030 Operator's Manual - Pump Capacity: 3PH 7.5 gpm, Power Steering 5.6 gpm. I do not know why they keep publishing the lower numbers in the sales brochure... but neither of these list @rpm.

Page 4 of BH70-X, BH-80X Operator's Manual - Operating flow: 5-7 gpm.

The Woods PTO pump puts out 6gpm at best. Purely from a flow standpoint, the B3030 kicks its butt and delivers all the 'hoe can use and then some. It's obvious that the PTO pump is completely unnecessary (and just another hassle to install/remove).

Anecdotally, my BH80-X has more than enough power to toss my B3030 around like a rag doll, if I'd let it. I have yet to need to run the 'hoe at more than about 1800 rpm. The ONLY thing that would make it dig better is a heavier tractor.

Now Go forth, buy wisely, and excavate!

 

[MadReferee]

Without naming names, there's a few ppl in this thread talking out their @ss - get your facts straight before you post clutter to mislead others!

Page 3 of B3030 Operator's Manual - Pump Capacity: 3PH 7.5 gpm, Power Steering 5.6 gpm. I do not know why they keep publishing the lower numbers in the sales brochure... but neither of these list @rpm.

Well, well, well. Before you go calling people names you should do some homework. ALL, and I mean ALL, of Kubota's product and pricing literature and their website says that the owners manual is WRONG. Now what or who are to we believe? You tell me since you have made yourself the expert.