Yes, the lines that carry continuous flow, even when the loader is not being used. Remember, this is an open center system.
What size are the lines on the tractor side? No point in making the new lines bigger than the existing ones on the tractor.
Front loader for a B7200
- Thread starter Paul Allwood
- Start date
What size are the lines on the tractor side? No point in making the new lines bigger than the existing ones on the tractor.
barts
Active member
Equipment
4wd B5100 w/ FEL, box blade, JD110 TLB, WC68 chipper, log arch, brush mower.
I converted a B219 Kubota loader that was in pieces to fit my B5100. Basically I had to make a new subframe, and devise a drive for the hydraulic pump. The arms, bucket and towers are from the original loader.
Thanks.
I've only measured the OD of the main lines on the tractor as follows:
- Main steel line from selector block to the back (to 3 pl controls ?) 12.0 mm - possibly 3/8" ID - yellow arrow in pics
- Main steel line from bottom of tank to pump (main suction line ?) 19.2 mm - ID ? - red arrow in pics
I guess based on this it would make sense to use 3/8" hydraulic lines from the right side of the hydraulic block to the loader valve inlet, and back from the loader valve power beyond to left side of the hydraulic block. Does this make sense ?
Attachments
Help understanding hydraulic block connections....
I think I've got the hydraulic selector block connections sorted (from Kubota manuals) for connection to the loader tomorrow, but I don't understand a couple of the lines on the hydraulic block.
In the attached pic, my understanding is:
1 - supply to loader valve
2 - return line from loader valve power beyond port
3 - supply to 3 point controls
4 - connection at the base of the hydraulic pump. Is the the pump outlet ?
5 - no idea. Looks like a large flexible hose, suction ?
Many thanks again from a hydraulics (and tractor) beginner.
I think I've got the hydraulic selector block connections sorted (from Kubota manuals) for connection to the loader tomorrow, but I don't understand a couple of the lines on the hydraulic block.
In the attached pic, my understanding is:
1 - supply to loader valve
2 - return line from loader valve power beyond port
3 - supply to 3 point controls
4 - connection at the base of the hydraulic pump. Is the the pump outlet ?
5 - no idea. Looks like a large flexible hose, suction ?
Many thanks again from a hydraulics (and tractor) beginner.
Attachments
It isnt going to matter one way or the other so do whatever makes you feel better.
The ONLY thing gained from using a larger hose for loader delivery and return is less heat is generated and on that tractor with a max of 4 GPM flow and those run lengths the difference is probably immesurable.
As a reference point a factory LA525 on a L3901 HST is conveying twice as much flow using 3/8" hoses.
Dan
Number 5 is used for the pressure relief unloader and loops back to the suction side of pump.
On a factory loader the loader valve tank return goes to the transmission filler.
Dan
Thanks Dan.
Do you know if that pressure relief unloader is sufficient to protect the pump if the pump outlet is closed ?
I'll also have the tank return from the loader valve go back to the transmission filler. It was originally just a filler cap, so I've replaced it with a tee - filler cap on top, return in the branch.
Attachments
The pressure relief in the outlet block controls the maximum pump outlet pressure and protects the pump from catastrophic over pressure if the outlet is deadheaded.
Like most Kubota systems it can operate for extended periods but prolonged operation will overheat the oil and stress both pump and valve eventually leading to premature failure.
Dan
That's what I would do. However, as @TheOldHokie points out, 4 gpm in 1/4" isn't very restrictive. (In my former career, I always tended to be generous in my line sizing.)
BTW, I see green, not red. Tell me I'm not color-blind
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ThanksThat's what I would do. However, as @TheOldHokie points out, 4 gpm in 1/4" isn't very restrictive. (In my former career, I always tended to be generous in my line sizing.)
BTW, I see green, not red. Tell me I'm not color-blind
It appears to work - I'm happy with that so far. Many thanks to everyone who has commented and offered advice so far.
I haven't made a bucket or any other attachments yet so can't use it, but I might try and see how close it can get to the rated lift capacity for a B7200.
Edit: Just used the tractor for spraying weeds and discovered that the 3 point hydraulics aren't working. Turns out there is an additional fitting required for the valve to make the power beyond port work. The part is on the way. So close.
I haven't made a bucket or any other attachments yet so can't use it, but I might try and see how close it can get to the rated lift capacity for a B7200.
Edit: Just used the tractor for spraying weeds and discovered that the 3 point hydraulics aren't working. Turns out there is an additional fitting required for the valve to make the power beyond port work. The part is on the way. So close.
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torch
Well-known member
Equipment
B7100HSD, B2789, B2550, B4672, 48" cultivator, homemade FEL and Cab
Looks pretty good, but that poor chair may not survive too many more tests... <lol>
When you are making your bucket, you will want it mounted so as it lifts the front end up about that same amount when flat on a flat surface. That will give you some digging depth while maximizing dump height.
Your max arm height looks pretty good and is still well forward of the front of the tractor. Your range of curl looks good, make sure you plan the bucket mounting angle to still allow some curl back. You want the bottom to be around 15°-20° from horizontal at the lowest position. Too much and you won't have enough dump angle to unload sticky material like mud.
Bear in mind that while operating you will need to curl the bucket down a bit as you raise it above the hood level to prevent material from spilling out the back and landing on your hood. Don't Ask Me How I Know This (tm)!
When you are making your bucket, you will want it mounted so as it lifts the front end up about that same amount when flat on a flat surface. That will give you some digging depth while maximizing dump height.
Your max arm height looks pretty good and is still well forward of the front of the tractor. Your range of curl looks good, make sure you plan the bucket mounting angle to still allow some curl back. You want the bottom to be around 15°-20° from horizontal at the lowest position. Too much and you won't have enough dump angle to unload sticky material like mud.
Bear in mind that while operating you will need to curl the bucket down a bit as you raise it above the hood level to prevent material from spilling out the back and landing on your hood. Don't Ask Me How I Know This (tm)!
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Thanks. Yeah, dodgy operator.
Planning on the level bottom of the bucket being able to be about 4" below ground level.
Haha - I'll be turning the valve into a joystick control for the raise/lower and curl/dump to try to help avoid tipping the load on myself.
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torch
Well-known member
Equipment
B7100HSD, B2789, B2550, B4672, 48" cultivator, homemade FEL and Cab
That works in theory...
With the low flow rate from the pump I find I can only get two functions to work at part flow on each -- especially when trying to fight gravity with one while going with gravity with the other. It's less critical with a bucket than forks due to the difference in leverage. Also, the things lifted with forks tend to slide around more than the things lifted in buckets.
With the low flow rate from the pump I find I can only get two functions to work at part flow on each -- especially when trying to fight gravity with one while going with gravity with the other. It's less critical with a bucket than forks due to the difference in leverage. Also, the things lifted with forks tend to slide around more than the things lifted in buckets.
Some of the things I make because I think I'll need them. Other times it's because I wonder if I can. I've zoomed in on a couple of videos of joystick valve mechanisms - wondering if I can turn my two levers into one.
I have a three spool valve (grapple, 4 in 1 bucket....) so the 3rd will still be a separate stick.