BH77 - has anyone considered converting mechanical thumb to hydraulic?

[CDN Farm Boy]

The OEM valve kit for these tractors for rear remotes is a poorly designed afterthought. Unless they have changed something, Kubota uses a bracket to mount the valve horizontally off the outside of the ROPS so it sticks WAY out to the side just asking to get hit on stuff.

For less money than a single spool OEM kit, I did my own setup with a 4 spool Prince valve from Surplus Center and mounted it vertically on the inside of my ROPS. Very happy with it.

 

[bumperm]

The OEM valve kit for these tractors for rear remotes is a poorly designed afterthought. Unless they have changed something, Kubota uses a bracket to mount the valve horizontally off the outside of the ROPS so it sticks WAY out to the side just asking to get hit on stuff.

For less money than a single spool OEM kit, I did my own setup with a 4 spool Prince valve from Surplus Center and mounted it vertically on the inside of my ROPS. Very happy with it.

For a non-cab tractor, that's been my experience with Kubota too, though that was back in 1989 :c).

On the B3350 cab, the rear remotes are built in nicely with a longish lever linkage that comes up through slots at the right rear of the cab and the valves themselves located down on the tractor case. The hydraulic outlets are the "safety pull-apart" quick connect type and mounted neatly inboard of the rear light.

Picture from when I was modifying a cylinder for tilt:

 

[briandantz]

Hi Bumperm, & CDN,
i am looking at squeezing a 2 spool joystick in adjacent to the 3 point lever where the draft control would go. the power would come from the line that feeds the backhoe, pressure in and power beyond to the hoe. (need to provide a tee at the tank connection to separate the power beyond and tank lines just like the loader valve up front.)

it looks like the BX guys have more challenges than the L guys. space is at a premium. forces one to do better planning or you end up with a hydraulic trellis of grape vines. the internet is full of pictures of bad hair days, especially in the front 3rd function area. Most BX guys seem to do well in smaller space. (and provide great photos)

BTW, been doing tons of reading on 3rd function and top/ tilt setups. It blows my mind how many people still do 3rd function with a regular 1 spool valve after the loader without power beyond. you can get a bath of oil if your hoe or 3 point puts too much back pressure on your added valve.

Heck, I was ready to add a lift table to my log splitter when i realized i was about to back pressure my existing 30 year old Prince valve with another downstream 1 spool table lift. Same rules apply. Tank ports go to tank, period.

 

[CDN Farm Boy]

If you have space on your L to fit down beside the seat, go for it. No way was I fitting 4 spool down there on my B.

May I suggest a slightly different plumbing arrangement: PB from the loader valve becomes the in for the new valve and tank return just as you say. Here's the difference: run the PB line from the new valve to the 3pt without connections for the BH. Run the BH off one pair of the work ports of the new valve. Hydraulic wise it will still function exactly the same as it does now off the PB loop but connection is much more simple when mounting/dismounting the hoe. You either need a value with detent or many just bungie cord the lever

If you look under my name at threads started, you can find the thread from when I did mine. I'd post the link but I'm on my phone and have no idea how to do it thru the app.

 

[briandantz]

i did read your post about this arrangement using the "A" port (bungee) as an aux to run a hoe. Interesting. Also keeps you from dead heading your machine if you fail to recouple your PB to 3PT coupler after you remove the hoe. (I haven't done this yet, but it's bound to happen)

The L series has a ton of room between the seat and the fender. more than a lunch box (dad's old one, not Scoobie-Doo!)

whats your thoughts on feeding the "a" ports from the rear remotes to the front as well to use for a grapple (tee'd front and back)? you can't use the concurrently and you wouldn't have the control up on the loader stick, but you would have to add an solenoid valve and switch either.

 

[bumperm]

Brian,

Not sure this would be a factor, but Kubota is emphatic about insuring the 3 pt lever remain full down when using power beyond for the hoe. As to forgetting to hook the PB quick connect when removing the hoe, I'm old and getting forgetful, but I don't think I'd ever get *that* forgetful! After relieving pressure on all the levers on the BH, when removing that hose QC from the hoe, it's rat there in my hand and I just route the hose through the holder clips and plug the QC back in on the tractor. Then I do the same with the loose hose end on the hoe.

 

[CDN Farm Boy]

whats your thoughts on feeding the "a" ports from the rear remotes to the front as well to use for a grapple (tee'd front and back)? you can't use the concurrently and you wouldn't have the control up on the loader stick, but you would have to add an solenoid valve and switch either.

Yup, I did that too. That's also how I power my hyd thumb on the hoe. That's part of why I went with a 4 spool, I knew I wanted 1 up front and 3 out back and this was the most cost effective way to do it. Is it 100% ideal? No but it works plenty fine for me.

Brian,

Not sure this would be a factor, but Kubota is emphatic about insuring the 3 pt lever remain full down when using power beyond for the hoe. As to forgetting to hook the PB quick connect when removing the hoe, I'm old and getting forgetful, but I don't think I'd ever get *that* forgetful! After relieving pressure on all the levers on the BH, when removing that hose QC from the hoe, it's rat there in my hand and I just route the hose through the holder clips and plug the QC back in on the tractor. Then I do the same with the loose hose end on the hoe.

The difference is once you are running the BH off the work ports, it's going back thru the tank return line rather than continuing thru the 3pt valve.

To me its not about being forgetful, its just easier because its less work. Using the PB loop, you are dealing with 3 connections each time (undo the loop and then connect the 2 BH lines) where I have only ever 2 to do (2 to mount or 2 to dismount)

 

[briandantz]

Bump,
Kubota (and many others) only have a 2 hose backhoe (no tank line) Well, "Tank" and "return" or "power out" become one in the same. By putting the 3 point lever fully forward to "float", the position controller on the 3 point basically becomes open to tank. Moving the lever back could conceivably cause the controller to lift the arms while he hoe is on.

this causes two possible outcomes.
1) the arms raise up , possibly interfering with some other object on the backhoe. (or some part of your person)
2) the pressure in the backhoe return line will start to climb, since you just magically turned its "tank" line into a "pressure line"

Oddly enough, Mahindra has a three hose backhoe with PB and tank separated so the BH return isn't restricted by the 3 PT. I looked at Mahindra like 2 hours before i bought my Kubota. lots of tractor and HP/dollar.

As for not reconnecting the lines. i will fail this eventually. Too many distractions. Every time i get near the tractor, some other task rears it's head.

 

[briandantz]

I ignored your comment earlier about the 4 spool because i thought it was a typo and you meant 2 spool. Cool. Big valve. You are on the top of the fender?

Years ago, I owed a Pay-loader that had rear loop for a high flow accessory. Hough H-50 1964. There was a Prince selector valve in the cab you would pull up to enable the loop. this was common on industrial equipment back then. Now, everything is an option. That loop on the Kubota for the backhoe should have always been a pair of rear remotes and a selector valve right from the factory.

 

[CDN Farm Boy]

Its actually not that big physically. Considering the flow of my tractor, I went with the 8 gpm valve which isn't that big.



I still need to build a cover plate for the hoses but that seems to keep moving further down the list of priorities

Top spool is 1/4" for BH thumb or snowblower chute deflector
2nd down is 1/4" and is used for snowblower chute rotation
3rd down is 3/8" with detent and used for BH, wood splitter, dump wagon and soon hyd top link
Bottom is 1/4" and run to the loader

If I ever find the need for a forth set at the back, I'll use the front one and replace it with a diverter valve.