Backhoe Independent hydro pump on backhoe

[8561]

Anyone know if the independent hydraulic pump option on a backhoe will increase its capacity? I have my backhoe working off the tractor hydraulics and decided not to go for the independent pump. I understand the risk of blowing a line and being stuck with my tractor which has been described in other posts. I'm really interested in knowing if the independent pump running off the PTO would be stronger (provide more digging capacity) than the remotes off my hydrauliuc system. I believe my tractor produces the gallons per minute the backhoe manufacturer specifies. Thanks for the help.

 

[DieselD]

Most of the time Yes it will work better with a PTO PUMP.
Check to see what your tractor pump puts out compared to the independent pump.
Danny

 

[MossRoad]

Power or speed?

If it is the more PSI than your tractor, I think it will provide more power.

If it is more GPM than your tractor, I think it will provide more speed.

If it is more PSI and GPM than your tractor, it should provide more power and speed.

Or something like that. /forums/images/graemlins/crazy.gif

 

[rambler]

You seem to be asking about 2 different things. I suspect a bigger hoe will increase your digging capacity, not a pto pump.....

Here's the deal: A pump with more gpm will increase the speed that your hoe moves.

A pump with more psi will increase the power your hoe has - until the limit of your hoe's relief valve, at which point increased psi is wasted.

You say your tractor already matches the recommended gpm (that's speed). Sometimes going faster is a bad, jerky, hard to control thing, I would not go far beyond what's recommended.

I would guess most newer tractors put out about 2000 psi, and most 3-point backhoes would have a pressure relief at about that. (This is diffing force - you didn't give us any info on what the tractor produces, what the hoe can use.)

Unless you can tell us more info to fill in the missing data (In what way are you trying to increase the hoe's preformance - speed or digging power? And what setting is everything at now?), I don't believe you will gain much preformance by going with a pto pump? You would need a bigger hoe.

--->Paul

 

[8561]

Thanks guys, I'll check and compare the PSI ratings. You are correct, I don't need or want more speed, but as always, more digging power would be nice. Can't go with a bigger hoe on my tractor.

 

[JerryG]

8651,
What you might do is have your dealer check to see if you reliefs are opening where they should. And have them check to see if your PSI is set to the high side of what is allowed. It has been proved here many times, a lot of tractors come from the factory with the pressure on the low side or below.

 

[Chipperman]

8561
Hello, I see you have a Wallenstein GX700 Backhoe is that a 7ft hoe? I have seen them at some of the trade shows. I was wondering how they worked. Did you compare the digging and break out force to other back hoes?

In regard to a PTO pump in your case I do not think it would help. Checking the relief valve would be a good idea but I suspect you are just up against the limits of that back hoe.
Good Luck
Chipperman

 

[BigEddy]

If your tractor puts out the recommended flow and psi, then there is one thing an independent pump can do, albeit with risks. - It can reduce the engine speed required to operate the hoe. This may save you fuel costs.

The hoe has a preset pressure limit. No matter what the rated pump pressure, the relief valves will operate at the same pressure, so you will not get more digging force no matter what pump you use. Change relief setting (your risk) , change cylinder size (your risk) and you can increase force, change pump you can't.

However pump output is proportional to engine speed. If your tractor pump puts out 10gpm (at PTO speed) and you install a 20gpm pto pump, you can run the engine at half rated speed for the same flow.

BUT!
You risk lugging the engine when you load down the hoe at half PTO speed.
AND
You have no mechanism to prevent running at PTO speed and feeding 20gpm to a hoe that's only sized for 10gpm.
AND
You could size the pump beyond your PTO HP, and lug the engine even at PTO speed!

Plus you now have a second pump, second (and larger) resevoir etc. to maintain. Buying a 12 GPM pump (versus 10) and running it at 80% speed would probably be low risk, but is it really worth it for the minor fuel savings? Even running at PTO speed is probably low risk, with slightly faster movement, but do you need more speed or force?

I'd check the tractor and hoe relief settings (there are individual relief valves on my hoe for separate circuits - not just one) and then chock it up to the capability/limitations of your hoe.

 

[8561]

Chipperman - The GX 700 is a 7' reach. I've only had it a few weeks but so far, so good. I had it painted Kubota orange and it looks good. Mine has a 12" bucket.
I had considered the Woods, the Kubota OEM and the Wallenstein. There were really two things that swayed me to my purchase. First was price. I paid less than I would have paid for the Woods 6500 and considerably less than the Kubota. I also figured I'd be happier with the 7' as opposed to the other two at 6.5'. My B2410 is only rated for 6.5' so I wasn't comfortable going to 7.5', but thought I could get away with 7. I may have been wrong but that was my judgement and the basis for my comparisons. I opted for a subframe assembly to help be safe.
As far as comparing, I thought it stacked up pretty well. I really compared it most closely to the Woods, due mostly to price. The reaches on the Wallenstein are greater due to it's slightly larger size. All the cylinder diameters on the Wallenstein are 2.5 inches while the Woods has dipperstick and bucket cylinders of 2 inches. Wallenstein dipperstick digging force is 1300 lbs, Woods is 1280. Wallenstein bucket digging force is 2600, Woods is 2600.
The only gray area for me was the unknown nature of Wallenstein as compared to Woods' good reputation. If I have significant issues, I will post them for all to see. The Wallenstein site is www.embmfg.com.

 

[8561]

Thanks Jerry, that's a great idea. It's not that I am unhappy with the digging force, I just am looking to maximize what I purchased. The Wallenstein spec sheet states the relief valve setting is at 2250 psi. Where it actually is and where my tractor is currently set is anyone's guess at this point. Thanks for the great advice.