B7100D hydraulics and adding a FEL

PKele

New member

Equipment
1981 B7100D
Apr 14, 2024
12
0
1
CA
Hi All,
I'm new here but have been lurking for quite a while trying to find some answers...I created an account to ask the questions directly and hopefully someone can help. My local Kubota dealership has been less than helpful.
I have a 1981 B7100D 4WD tractor, NOT a hydrostatic drive. I got it for the great price of free but it did not come with a FEL. I'm looking to add one and am looking at the Westendorf TA-55. They suggest a 6gpm pump at least.
My question for all of you is:
1. can the stock pump bolted to the block supply the oil needed for a FEL? I see some later B7100HST models that have a T off the pressure line running from the pump to the transmission but I figured that it's an upgraded pump because of the hydro demands. I also see early B7100's with a front mount pump, which leads to my second questions.
2. I see that there is a PTO spline flange PN 66704-88530 and it would seem to have a spline that will fit my stub. That part is to adapt the electric clutch for a belly mower or other belt driven implement. Is there a Kubota spline drive for a front mount pump? I know they exist and were a factory option so I'm hoping that a PN exists.

Thanks everyone!
 

North Idaho Wolfman

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The hydraulic pumps between the Geared and HST are the same 3GPM, the hydrostatic uses its own pump for the drive portion of things.

You can run a loader off the on board hydraulic pump it just will be slow.

To add a pump off the crank you will need to make your own parts are the factory parts are long obsolete.
The were mutiple variations of the drives that were used for it.
 

TheOldHokie

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windyridgefarm.us
Hi All,
I'm new here but have been lurking for quite a while trying to find some answers...I created an account to ask the questions directly and hopefully someone can help. My local Kubota dealership has been less than helpful.
I have a 1981 B7100D 4WD tractor, NOT a hydrostatic drive. I got it for the great price of free but it did not come with a FEL. I'm looking to add one and am looking at the Westendorf TA-55. They suggest a 6gpm pump at least.
My question for all of you is:
1. can the stock pump bolted to the block supply the oil needed for a FEL? I see some later B7100HST models that have a T off the pressure line running from the pump to the transmission but I figured that it's an upgraded pump because of the hydro demands. I also see early B7100's with a front mount pump, which leads to my second questions.
2. I see that there is a PTO spline flange PN 66704-88530 and it would seem to have a spline that will fit my stub. That part is to adapt the electric clutch for a belly mower or other belt driven implement. Is there a Kubota spline drive for a front mount pump? I know they exist and were a factory option so I'm hoping that a PN exists.

Thanks everyone!
The implement pump delivers 3 GPM. Now whats the bore and stroke of the lift and bucket cylinders on the loader. That will tell us the cycle time and you can decide if thats acceptable or not. I have a B7200 with factory B1630 loader which has been running off that same pump for 30 years and I never worried about speed.

If you want a larger crankshaft driven pump its a custom fabrication DIY project. The factory parts are rare as Unicorns. Building a custom drive is not super hsrd but it does require tools and fabrication skills.

Dan
 

tsp159

Member

Equipment
B7100D
Feb 8, 2023
98
50
18
Fort Bend Texas
1. can the stock pump bolted to the block supply the oil needed for a FEL? I see some later B7100HST models that have a T off the pressure line running from the pump to the transmission but I figured that it's an upgraded pump because of the hydro demands. I also see early B7100's with a front mount pump, which leads to my second questions.
Like @TheOldHokie my B7100HST-D has a B1630 loader and runs off the stock hydraulic pump. It uses some 2" cylinders for all the lift and curl functions and is perfectly fine, just a little slower. You will need a hydraulic "block" that permits you to add the loader into the rear implement circuit. @torch used to machine these and sell them when he had a batch. Very nice and worked perfectly.

This will work better for you than trying to cobble a crank driven pump, in my opinion.
 

TheOldHokie

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L3901/LA525, B7200DT/B1630, G2160/RCK60, G2460/RCK60
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windyridgefarm.us
Like @TheOldHokie my B7100HST-D has a B1630 loader and runs off the stock hydraulic pump. It uses some 2" cylinders for all the lift and curl functions and is perfectly fine, just a little slower. You will need a hydraulic "block" that permits you to add the loader into the rear implement circuit. @torch used to machine these and sell them when he had a batch. Very nice and worked perfectly.

This will work better for you than trying to cobble a crank driven pump, in my opinion.
The cylinders on my B1630 are 1.5" bore.

Dan
 

PKele

New member

Equipment
1981 B7100D
Apr 14, 2024
12
0
1
CA
Thanks for all the replies, it's a big help. I may delay fabricating the front mount pump for a while and do as you all suggest with the inline 'block' from the pump pressure and return lines.
I don't mind the fabrication of the front pump mount, but fabricating an internal spline is a bit more work than I'd like to do right now.

What are you guys thoughts on inline hydraulic tee fitting? I got the loader on order and may not be able to wait for the block, I'm on a bit of a time crunch.
Something like this: https://www.hydraulicsdirect.com/ProductDetails.asp?ProductCode=47655
 

North Idaho Wolfman

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Thanks for all the replies, it's a big help. I may delay fabricating the front mount pump for a while and do as you all suggest with the inline 'block' from the pump pressure and return lines.
I don't mind the fabrication of the front pump mount, but fabricating an internal spline is a bit more work than I'd like to do right now.

What are you guys thoughts on inline hydraulic tee fitting? I got the loader on order and may not be able to wait for the block, I'm on a bit of a time crunch.
Something like this: https://www.hydraulicsdirect.com/ProductDetails.asp?ProductCode=47655
You CAN NOT tee the hydraulics.
It needs to be a loop, power in, power out.
 

TheOldHokie

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L3901/LA525, B7200DT/B1630, G2160/RCK60, G2460/RCK60
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windyridgefarm.us
Thanks for all the replies, it's a big help. I may delay fabricating the front mount pump for a while and do as you all suggest with the inline 'block' from the pump pressure and return lines.
I don't mind the fabrication of the front pump mount, but fabricating an internal spline is a bit more work than I'd like to do right now.

What are you guys thoughts on inline hydraulic tee fitting? I got the loader on order and may not be able to wait for the block, I'm on a bit of a time crunch.
Something like this: https://www.hydraulicsdirect.com/ProductDetails.asp?ProductCode=47655
I can turn a block out pretty quickly. Send me a PM. Or roll your own. Note the use of an implement valve with inlet pressure relief - item 8 in the circuit diagram. That is mandatory if you value the health of your hydraulic pump:

1000002605.jpg


You can fabricate a crankshaft drive without cutting any splines.

Dan
 
Last edited:

PKele

New member

Equipment
1981 B7100D
Apr 14, 2024
12
0
1
CA
Ah, right forgot about that with hydraulics... It's been a while since I've had to deal with hydraulic systems.

Well, if I cannot get my hands on a block in time, I suppose I could break the pressure line after the pump, before the transaxle and use a couple of compression elbows to quick disconnect fittings, correct? One QD on a flex line and the other on the elbow. When the loader is off, the QD's connect to themselves, when the loader is attached, they connect to the corresponding lines from the loader, right? That's all the block does, correct?

The FEL valve and joystick has a pressure relief valve built in I believe.
 

TheOldHokie

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windyridgefarm.us
Ah, right forgot about that with hydraulics... It's been a while since I've had to deal with hydraulic systems.

Well, if I cannot get my hands on a block in time, I suppose I could break the pressure line after the pump, before the transaxle and use a couple of compression elbows to quick disconnect fittings, correct? One QD on a flex line and the other on the elbow. When the loader is off, the QD's connect to themselves, when the loader is attached, they connect to the corresponding lines from the loader, right? That's all the block does, correct?

The FEL valve and joystick has a pressure relief valve built in I believe.
You can cut the line and add fittings to create the takeoff. That is all the block dirs. Given you have the OEM base block in the line and the other half is a couplevdays out that would not be high on my list.

Your loader valve should be plumbed with both power beyond and tank returns to the tractor.

Dan
 
Last edited:

PKele

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Equipment
1981 B7100D
Apr 14, 2024
12
0
1
CA
Unfortunately I do not have any OEM block on this tractor. There are 2 lines running uninterrupted from the pump to the transaxle, that's it.
 

PKele

New member

Equipment
1981 B7100D
Apr 14, 2024
12
0
1
CA
I think this is the last question for you all!
Perhaps the best action would be to use the hydro diverter valve under the B7100 seat and then fabricate a return to the threaded fill plug for the trans-axle? I won't be using the 3-point and the loader at the same time.
I had read on a couple of forums that this option is a more restricted route and will slow down the FEL operation more than just tapping into the pressure feed line. Is there any truth to that?
 

tsp159

Member

Equipment
B7100D
Feb 8, 2023
98
50
18
Fort Bend Texas
Unfortunately I do not have any OEM block on this tractor. There are 2 lines running uninterrupted from the pump to the transaxle, that's it.
Get a diverter block cover from @TheOldHokie or @torch. That is the right way to do it. I added a loader to my B7100HST and routed the fluid from the block (forward/right hand port) up to my loader valve (with internal relief) out of the power beyond port and back to the block (rear/left hand port) which goes to the 3-pt valve. The loader valve does have a tank connection for the relief, and it is routed to the fill port on the trans tunnel.
 
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TheOldHokie

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I think this is the last question for you all!
Perhaps the best action would be to use the hydro diverter valve under the B7100 seat and then fabricate a return to the threaded fill plug for the trans-axle? I won't be using the 3-point and the loader at the same time.
I had read on a couple of forums that this option is a more restricted route and will slow down the FEL operation more than just tapping into the pressure feed line. Is there any truth to that?
With a loader you are going to want ballast on tje rear. You will inevitably want to use the 3pt with the loader mounted. I suspect you will also find a need for hydraulic outlets for some other implement somewhere down the line. I would tap into the pump supply but thats your call.

Dan
 
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North Idaho Wolfman

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L3450DT-GST, Woods FEL, B7100 HSD, FEL, 60" SB, 743 Bobcat with V2203, and more
Jun 9, 2013
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6,369
113
Sandpoint, ID
I think this is the last question for you all!
Perhaps the best action would be to use the hydro diverter valve under the B7100 seat and then fabricate a return to the threaded fill plug for the trans-axle? I won't be using the 3-point and the loader at the same time.
I had read on a couple of forums that this option is a more restricted route and will slow down the FEL operation more than just tapping into the pressure feed line. Is there any truth to that?
No, the diverter valve will be a poor choice for a feed location because it would require you to engage the three point lever all the time.
If you do not have the diverter block on the tractors hydraulic line, all the talk of getting the cover (tap block) to bolt onto it is pointless.
So do as you have said and cut the line and add fitting and hoses off that to power the loader, and yes add the third Tank line back to the fill port.
 
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PKele

New member

Equipment
1981 B7100D
Apr 14, 2024
12
0
1
CA
Thanks guys, this makes sense. I've got a plan, I'll break the line and add the fitting and replicate what the block does, addding the tank line back as well. I appreciate your guys time. I'll let you know how it turns out!
 

PKele

New member

Equipment
1981 B7100D
Apr 14, 2024
12
0
1
CA
Hey guys, just wanted to give an update.
I've had the Westendorf TA55 frontloader on there for a while now with no problems! I've got ~25 hrs of heavy front loader work with no issues.

I ended up fabricating a pump shaft using the female spline of flange 66704-88530 to 3/4" keyway stock and a Lovejoy coupling for the engine-to-pump connection. Pump is a NorTrac CBS6-F6. 3SS.
I built pump mount in cad and had Send Cut Send cut the steel and welded it up in place.
Hydraulic tank is an old steel scuba tank that I modified using parts cut by Send Cut Send.

I have cad for the pump mount if anyone would like it. I attached some pics for reference.

Thanks again for all the help.
 

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torch

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B7100HSD, B2789, B2550, B4672, 48" cultivator, homemade FEL and Cab
Jun 10, 2016
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113
Muskoka, Ont.
How many GPM do you figure you are getting out of it at operating RPM?