Upgrade compatibility for hydraulic pump?

PoTreeBoy

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I've never blown a flake of snow with a tractor, but I've seen others on here praise HST and 4WD when moving snow. Are you sure you'll be satisfied with your tractor if you go through with this?

There seems to be a valve size break around 20 - 21 GPM. If that's adequate, you could stay with a smaller valve and maybe decrease the suction line size.

If you're replacing your loader valve, you might could pipe your 3PH to the existing pump, like it would have been originally without the loader. Then buy a 4 or 5 section valve for the loader, blower and whatever else. You could go to a joystick on the loader and maybe clean up the piping. At greater cost, of course.
 

TheOldHokie

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I've never blown a flake of snow with a tractor, but I've seen others on here praise HST and 4WD when moving snow. Are you sure you'll be satisfied with your tractor if you go through with this?

There seems to be a valve size break around 20 - 21 GPM. If that's adequate, you could stay with a smaller valve and maybe decrease the suction line size.

If you're replacing your loader valve, you might could pipe your 3PH to the existing pump, like it would have been originally without the loader. Then buy a 4 or 5 section valve for the loader, blower and whatever else. You could go to a joystick on the loader and maybe clean up the piping. At greater cost, of course.
How is he going to run the 3pt off an wxternal reservoir?

Dan
 

TheOldHokie

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I've never blown a flake of snow with a tractor, but I've seen others on here praise HST and 4WD when moving snow. Are you sure you'll be satisfied with your tractor if you go through with this?

There seems to be a valve size break around 20 - 21 GPM. If that's adequate, you could stay with a smaller valve and maybe decrease the suction line size.

If you're replacing your loader valve, you might could pipe your 3PH to the existing pump, like it would have been originally without the loader. Then buy a 4 or 5 section valve for the loader, blower and whatever else. You could go to a joystick on the loader and maybe clean up the piping. At greater cost, of course.
My bad - I miss read that. Bottom line is it needs to be two separate systems and any additions are easiest made on the higher flow add on system.

Dan
 

PoTreeBoy

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My bad - I miss read that. Bottom line is it needs to be two separate systems and any additions are easiest made on the higher flow add on system.

Dan
Agree. Actually, this base tractor may have come with a SA auxiliary. There's an old manual at Kubotabooks.com that implies that. It looks like that valve could be modified/replaced with the loader valve.

Come to think of it, that SA (and loader valve) shows a relief valve in it, and if OP takes it out of the system, he'll need to make sure he has a relief valve in that system. I can't tell if the 3PH has one.
 

TheOldHokie

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Agree. Actually, this base tractor may have come with a SA auxiliary. There's an old manual at Kubotabooks.com that implies that. It looks like that valve could be modified/replaced with the loader valve.

Come to think of it, that SA (and loader valve) shows a relief valve in it, and if OP takes it out of the system, he'll need to make sure he has a relief valve in that system. I can't tell if the 3PH has one.
I would not touch the existing system other than to upgrade the existing hoses. Add the new pump with reservoir and whatever additional valves you want for additional functions and be done. Expect to spend the better part of $3k for that.

Dan
 
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Oktm

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Thank you all for input on this! I am mostly just trying to figure out what my options are here and how to proceed. It sounds like my cheapest option would be a reservoir, PTO pump, and lines long enough to reach the front and just run the blower without a valve and the nicest would be to run a crank driven pump and replace all the valved devices with a new set of valves. I am going to go through and try to figure out what actual parts I would need for the latter and see what I am looking at. Thank you again!
 

TheOldHokie

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Thank you all for input on this! I am mostly just trying to figure out what my options are here and how to proceed. It sounds like my cheapest option would be a reservoir, PTO pump, and lines long enough to reach the front and just run the blower without a valve and the nicest would be to run a crank driven pump and replace all the valved devices with a new set of valves. I am going to go through and try to figure out what actual parts I would need for the latter and see what I am looking at. Thank you again!
I have done more than a few conversions of this type. Your reservoir cost is going to be the same either way and the difference in cost for the front pump is basically going to be the new valve.

A 21 GPM PTO pump is going to run you at least $425 plus shipping. Unless you want to spend double that you are not going to get more flow with a PTO pump.

Here is a basic BOM and prices for the front pump and valve components. An SAE B two bolt pump will bolt up to the front of teh tractor with minimum fabrication. You can easily get higher flows at the same cost with this type pump.
  1. Dynamic SAE B 25-30 GPM gear pump - $240
  2. Chain coupler and shaft for pump - $75
  3. Brand 45 GPM motor control valve - $290
So you see you can do the higher capacity front pump with a motor valve and keep your existing remote valves for essentially the same cost as a smaller PTO pump with no motor valve.

Now if you want to replace or augment the exiting remotes the cost gets a bit higher and you start to push the flow rating on the valve. This valve is rated 20 GPM which is probably not an issue at the 25 GPM rate - you will just get a slightly larger pressure drop across the valve.
  1. Prince S20 sectional valve with one motor spool - $460.
  2. Additional double acting work sections for valve - $200 each
  3. Additional single acting work sections for valve - $113 each
Dan
 
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Oktm

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It seems super strange that the PTO pumps are so much more, but that makes sense and seems like the way to go then, Now to track those puppies down! Thank you!
 

TheOldHokie

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It seems super strange that the PTO pumps are so much more, but that makes sense and seems like the way to go then, Now to track those puppies down! Thank you!
Surplus Center has the reservoir, pump, and drive components. Shipping on that reservoir could be hefty. They also have the Prince valve but I just priced a different one which is a little less expensive. Also make sure you match the rotation of the pump to the engine - should be a counter - clockwise pump.

Did you ever measure the bolt hole spacing on the front of the tractor?

Dan
 

Oktm

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I have been busy with work and have not been able to get out there this week, but hopefully I will be able to go later today (Finishing our house and renting right now) I was building a parts list:
and one of these two:
+
or
+
I do have some questions though. I was originally going to go with one of the splined pumps, but they don't carry the splined stock for the shaft, nor an adapter coupler. I went with keyed, but the key on the pump is 1/4" on a 7/8 shaft and again there is not adapter coupler to the 3/16" on 7/8" that everything else uses. I am sure everything is hardened and therefore will be a nightmare, but at least I could grind down the key on the pump or enlarge the keyway on the coupler. Is there a better option? Also, is there a path where I don't have to order 10' of chain? :D
One last thing, is there a good guide to the terminology of hydraulic systems? I have a fair amount of automotive modification and repair, but this is my introduction to hydraulics and I keep running into terminology like "prince valves" (Is there a peasant valve?), Power Beyond, etc...
Thank you for all the advice!
 

TheOldHokie

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I have been busy with work and have not been able to get out there this week, but hopefully I will be able to go later today (Finishing our house and renting right now) I was building a parts list:
and one of these two:
+
or
+
I do have some questions though. I was originally going to go with one of the splined pumps, but they don't carry the splined stock for the shaft, nor an adapter coupler. I went with keyed, but the key on the pump is 1/4" on a 7/8 shaft and again there is not adapter coupler to the 3/16" on 7/8" that everything else uses. I am sure everything is hardened and therefore will be a nightmare, but at least I could grind down the key on the pump or enlarge the keyway on the coupler. Is there a better option? Also, is there a path where I don't have to order 10' of chain? :D
One last thing, is there a good guide to the terminology of hydraulic systems? I have a fair amount of automotive modification and repair, but this is my introduction to hydraulics and I keep running into terminology like "prince valves" (Is there a peasant valve?), Power Beyond, etc...
Thank you for all the advice!
Don't muck with grinding shafts and keyways . Give me your dimensions and I will make you a shaft and coupler with all the correct keyways. Pump end is 7/8" shaft with 1/4" keyway. Tractor end is 7/8" shaft with 3/16 keyway. How long should it be? None of this stuff is hardened. PM me.

Prince is just a manufacturer like Cross, Bucher, Eaton, and a host of others. Your system is purely open center and no power beyond.

Dan
 
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Oktm

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Don't muck with grinding shafts and keyways . Give me your dimensions and I will make you a shaft and coupler with all the correct keyways. Pump end is 7/8" shaft with 1/4" keyway. Tractor end is 7/8" shaft with 3/16 keyway. How long should it be? None of this stuff is hardened. PM me.

Prince is just a manufacturer like Cross, Bucher, Eaton, and a host of others. Your system is purely open center and no power beyond.

Dan
I'll measure things out when I get out there today and get them back to you. I will try to get a measurement on that existing chain coupler too (Looks like diameter of about 3" for the 40P and 3-3/4 for a 50P).
The coupler on the site will be a female 7/8" w/ 3/16 keyway and the pump is a male 7/8" with 1/4" keyway. I will get a measurement from the face of the coupler sprocket to the face that the pump will mount to. It looks like the pump shaft protrudes 1.81" past that point. The coupler sprocket from SC looks to have a depth of 1.58" if it is a 40P or 1.77" if it is a 50P and of course will need a bit of space from the face of the mating sprocket.
Also, do you happen to have some extra chain I could buy so I don't have to pick up a 10' box?
 

TheOldHokie

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I'll measure things out when I get out there today and get them back to you. I will try to get a measurement on that existing chain coupler too (Looks like diameter of about 3" for the 40P and 3-3/4 for a 50P).
The coupler on the site will be a female 7/8" w/ 3/16 keyway and the pump is a male 7/8" with 1/4" keyway. I will get a measurement from the face of the coupler sprocket to the face that the pump will mount to. It looks like the pump shaft protrudes 1.81" past that point. The coupler sprocket from SC looks to have a depth of 1.58" if it is a 40P or 1.77" if it is a 50P and of course will need a bit of space from the face of the mating sprocket.
Also, do you happen to have some extra chain I could buy so I don't have to pick up a 10' box?
Surplus Center sells the chain couplers as two halves and a chain loop. You buy the individual pieces to match your application so you can get one coupler half and a chain loop to fit the tractor. If its #40 chain I have those parts here.

The pump shaft/coupler is easily made from DOM tube - just bore, broach, and add set screws. It can even be welded to the intermediate shaft to make a one piece assembly.

If you are lucky the bolt holes on the tractor will match the flange on the pump. If not a simple adapter plate will get it mounted.

Like I said I do these all the time and its not expensive.

Dan
 

Oktm

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Kubota M7500DT
May 12, 2022
38
3
8
Utah
Surplus Center sells the chain couplers as two halves and a chain loop. You buy the individual pieces to match your application so you can get one coupler half and a chain loop to fit the tractor. If its #40 chain I have those parts here.

The pump shaft/coupler is easily made from DOM tube - just bore, broach, and add set screws. It can even be welded to the intermediate shaft to make a one piece assembly.

If you are lucky the bolt holes on the tractor will match the flange on the pump. If not a simple adapter plate will get it mounted.

Like I said I do these all the time and its not expensive.

Dan
I was looking for just the loop hoping it would come with a connecting link so I didn't have to figure all that out as well, but I was struggling to find it. Do you have a link to the 50P loop in case I need to pick one of them up as well?
 

TheOldHokie

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Oktm

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Kubota M7500DT
May 12, 2022
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I do not have any of #50 parts. Heres the loop for those couplers - includes the master link. Shipping to Oklahoma probably a lot cheaper than the east coast.

Dan

Forgot to measure the diameter of the sprocket, but I will be back up there later. The holes for the pump are 4-3/16" apart and the face of the sprocket is 21-3/8 from the face that the pump mounts to. IMG20220527112858.jpg IMG20220527112831.jpg
 

TheOldHokie

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Forgot to measure the diameter of the sprocket, but I will be back up there later. The holes for the pump are 4-3/16" apart and the face of the sprocket is 21-3/8 from the face that the pump mounts to. View attachment 80856 View attachment 80857
That's setup for an SAE A flange - dead on the money at 4.188 bolt circle. It would be a direct bolt on pump. Those pumps max out at around 2 CID which gets you 20 GPM @ 2500 RPM.

If you wanted to move up to a larger SAE B flange pump you would need an adapter plate. Real simple to make - just a piece of 3/8 thick plate to act as a spacer with a 4.5" pilot hole and two 4.75" bolt holes. You would have to drill two new holes in the tractor flange. Those pumps can easily hit 20+ GP @2000 RPM. They are also considerably larger. How much open space is there to fit the pump in?

Dan