pto pump question

i recently bought a john deere 850 tractor it has the factory jd 75 loader on it as well as a add on 3 point backhoe, the backhoe runs off a pto pump, but its not putting out enough volume, this thing looks almost like a small winch motor, the problem is the backhoe operation is beyond slow, its just almost unusable, plus you can only move one control one way at a time, what kind of pto pump should i look at to get this thing working like it should, i realize its not a commercial backhoe, but for the few times we need it, it will work ok if we can get the thing up to speed

John Deere, or other backhoe?

I would check the backhoe Operator's Manual for recommended GPM for the backhoe, then go to Surplus Center . com and select a pump based on PTO rotation and PTO speed at the engine speed you intend to operate at vs. the required GPM's and the capacity of the selected pump at that speed.

(quoted from post at 21:28:31 10/24/15) i recently bought a john deere 850 tractor it has the factory jd 75 loader on it as well as a add on 3 point backhoe, the backhoe runs off a pto pump, but its not putting out enough volume, this thing looks almost like a small winch motor, the problem is the backhoe operation is beyond slow, its just almost unusable, plus you can only move one control one way at a time, what kind of pto pump should i look at to get this thing working like it should, i realize its not a commercial backhoe, but for the few times we need it, it will work ok if we can get the thing up to speed

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I would plumb the backhoe into the tractor hydraulics. Who ever used the pto pump, did so because they had no idea how to tie into the open center hydraulics.

I once had a Kubota with a three point back hoe with PTO pump an it was FAST! IIRC the pump was less than six inches in diameter. May be there is a problem with the pump or plumbing or even something like a filter.

buick, that would depend upon the flow requirements of the backhoe.

Looks like the 850 had two pump options available, 4.75 or 5.25 GPM, and I'm gonna GUESS the larger one was for use with power steering.
5 GPM's, more or less, ain't a whole lot, of course, it's a small backhoe.

i have a long backhoe for my kubota, works ok but no way i'd plumb it into my remotes, no more then it gets used it always seems to condense water and the oil is milky

i made a mistake, as i didnt include info this backhoe on the tractor is an unknown make, why i dont know, but the p o removed all identifying tags on it, it is a small backhoe but the bucket is about a foot across and about 18 inches long, the cylinders are 2 inch diameter so it should have decent power for its size, its black so im thinking it is possibly a great neck, but not sure, i looked at the northern catalog and the 119.00 special hydraulic pump looks like what is on the tractor which states it has around 7 gpm, on the other page they have 2 bigger pumps one for 11 gpm and one for 21 gpm, both in the upper 500 dollar range which would you guys recomend also the tractor data states the jd 850 is rated at 22 hp, its a nice tractor but not a powerhouse, im new at trying to fix hydraulic issues my dump trucks had pumps but thats a whole different setup

(quoted from post at 22:14:30 10/24/15) buick, that would depend upon the flow requirements of the backhoe.

Looks like the 850 had two pump options available, 4.75 or 5.25 GPM, and I'm gonna GUESS the larger one was for use with power steering.
5 GPM's, more or less, ain't a whole lot, of course, it's a small backhoe.

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2-3 gpm will wail that small backhoe around faster than an operator can handle it.

a 2x18 cylinder has a volume of 127 cu inches. Thats a half gallon. With a 2 gpm pump thats a full 15 seconds to fully extend that cylinder. I'd go for a 10 gpm pump. You can always throttle the pto back to a speed you are comfortable with. Impossible to speed up a too small pump.
AaronSEIA

(quoted from post at 12:05:55 10/25/15) a 2x18 cylinder has a volume of 127 cu inches. Thats a half gallon. With a 2 gpm pump thats a full 15 seconds to fully extend that cylinder. I'd go for a 10 gpm pump. You can always throttle the pto back to a speed you are comfortable with. Impossible to speed up a too small pump.
AaronSEIA

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The ram is rarely taken over 1/2 stroke . Your calculation also skipped the volume taken up by the rod.
The factory 2500rpm , 13gpm pump when operated at 1200rpm on my much larger JD 10A . It supplies more oil than what any operator can keep up with.

You need to make sure you don't have a screen or filter plugged up before worrying about a new pump. Might be a bad suction hose.