how many GPM is needed

   / how many GPM is needed #41  
I'm shopping 40-50 hp hobby farm tractor like Kubota, TYM, Mahindra, Kioti new and used. Trying to compare apples to apples I see hydraulic gpm varies a lot. What is a good number for this size? Some tractor have 2 pumps - 1 dedicated to steering, so what's a good number for that one too? Thanks for any help.
When I can I follow this rule of thumb. “It is better to have it and not need it than need it and not have it”
That said you can go way over board too.
You are vague on what you want to attach to the tractor. I would suggest all will supply enough volume to do what you want. Best to check against what attachments you have/may use need though.
I would suggest that you get two rear valves/quick connections. Again better to have it and not need it than need it and not have it
 
   / how many GPM is needed #42  
IF you need flow requirements that exceed the 8-10gpm of the typical 40-50hp machine......simply get a PTO pump. Tractors, for their size and HP.....have relatively small pumps. Because they arent geared toward running high demand hydraulics like skidloaders are. Thats what they have a PTO for. Most tractor implements run off the PTO. But with 40hp at the PTO.....you can get up around 20GPM off a PTO pump @ 2500psi as long as you dont ALSO need the HP to drive the machine at the same time
Some PTO pumps also have a thru shaft. This PTO extension allows use of a PTO implement while leaving the pump in place, permanently.

Example, PTO pump to run a loader. Need to power an implement off the PTO and use the loader. It's a clumsy way of doing things, but works.

CT
 
   / how many GPM is needed #43  
I'm shopping 40-50 hp hobby farm tractor like Kubota, TYM, Mahindra, Kioti new and used. Trying to compare apples to apples I see hydraulic gpm varies a lot. What is a good number for this size? Some tractor have 2 pumps - 1 dedicated to steering, so what's a good number for that one too? Thanks for any help.
Pump flow:12 gpm
45.4 lpm
Total flow:17.5 gpm
66.2 lpm
For PTO and loader usage this should be your minimum. Anything less will probably disappoint you later on.
This is specs. on Workmaster 50, 4x4 with gear transmission and loader. (5.5 gpm of the Total flow is for power steering)

 
   / how many GPM is needed #44  
There isn't one that I know of.
I agree. Essentially all the name-brand tractors will have adequate hydraulic flow to do whatever you may likely do with them. The main exception I know of is flow to support hydraulic motor driven things like a front end loader mounted brush cutter and anything hydraulic motor driven.
 
   / how many GPM is needed #45  
I'm shopping 40-50 hp hobby farm tractor like Kubota, TYM, Mahindra, Kioti new and used. Trying to compare apples to apples I see hydraulic gpm varies a lot. What is a good number for this size? Some tractor have 2 pumps - 1 dedicated to steering, so what's a good number for that one too? Thanks for any help.

Flow and pressure don't really vary all that much on similar sized tractors. The way it is calculated by the advertising dept. accounts for much of the variation. For instance, do they include power steering? At what RPM?

You can always mount a PTO-powered pump with a reservoir on the 3pt of any tractor.
I agree with LD1 when he says it's easy. You can do it yourself or if you want one already built, several companies sell a 3 pt mounted reservoir and PTO pump all ready to go with accessory outputs. You may not need 20 gpm at full pressure and may well end up just using the standard 50 hp tractor hydraulics - it costs nothing to try it that way and your tractor will probably surprise you.

If not, the cost of the complete 3pt high output pump and reservoir is in the under $4K range. Expensive, but not enough so to change what tractor you buy. I used to have one on a 33 hp tractor for running a big splitter with a Cat cylinder, and that PTO pump had huge flow and pressure with the tractor running half throttle.

rScotty
 
   / how many GPM is needed #46  
Some tractors use cheap valves that won’t curl and lift at the same time. I’d be way more concerned about that vs hydraulic flow.
Disagree. It is not cheap valves, it is paying for (or not paying for) diverters or flow splitters. Nearly all tractors you might consider run open center hydraulics also known to me as "one track mind hydraulics." With open center whatever valve you open to do something inherently precludes other hydraulically powered activity from that same pump high pressure line. Most loaders (such as and including my own MF DL250 loader) will NOT curl and lift at the same time. Some tractors and loader valve configurations include a flow splitter or diverter that allows 2 things to be hyd driven at once but with less oomph. Most do not (though diverters/splitters may be more common as time goes on.)
The majority of utility tractors in the field today use loaders that are one track minded. And will NOT both curl and lift at the same exact time. There are many ways to obscure these facts and make the loaders (and other implements) APPEAR to do two driven things at once by using gravity as the other source. So usually you can dump while lifting, you can lift while dumping, etc. but only one hyd powered action at a time.
 
   / how many GPM is needed #47  
A bigger concern to me is can I make my hydraulics work slow enough. The maximum flow rate has never been an issue, but if the controls don't work well at allowing you to establish a miniscule flow without being forced to use micrometer like movements, that's can be a problem at times.
 
   / how many GPM is needed #48  
Flow and pressure don't really vary all that much on similar sized tractors. The way it is calculated by the advertising dept. accounts for much of the variation. For instance, do they include power steering? At what RPM?

You can always mount a PTO-powered pump with a reservoir on the 3pt of any tractor.
I agree with LD1 when he says it's easy. You can do it yourself or if you want one already built, several companies sell a 3 pt mounted reservoir and PTO pump all ready to go with accessory outputs. You may not need 20 gpm at full pressure and may well end up just using the standard 50 hp tractor hydraulics - it costs nothing to try it that way and your tractor will probably surprise you.

If not, the cost of the complete 3pt high output pump and reservoir is in the under $4K range. Expensive, but not enough so to change what tractor you buy. I used to have one on a 33 hp tractor for running a big splitter with a Cat cylinder, and that PTO pump had huge flow and pressure with the tractor running half throttle.

rScotty
1 thing not covered so far is return plumbing, on almost any of the CUT tractors if you are going to use a heavy motor on the hydraulics (some thing that requires RPMs to work like a brush mower not auger) you will need a dedicated return line.
 
   / how many GPM is needed #49  
1 thing not covered so far is return plumbing, on almost any of the CUT tractors if you are going to use a heavy motor on the hydraulics (some thing that requires RPMs to work like a brush mower not auger) you will need a dedicated return line.

That's true, and since the pressure is low then most any hose will work. But to be smart about it, and use a hose rated for hydraulic oil so that you don't get particles. The fittings can be radiator hose clamp type, but when the additional return line intercepts the existing return line (you can run one into the other and combne flows if you then oversize the return hose from that point) and use a Y connector to avoid the back pressure you can get with a T connector.
rScotty
 
 
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