Backhoe BT750B Auto return conversion to Manual
- Thread starter Ken speirs
- Start date
• Those diagrams help. I can see that the B20 is routed differently than the L35, so my warning isn't necessary. You do have a directional valve, but it's associated with the loader. There is a hose on the back of the tractor which needs to be looped for everything to function correctly. Please post a picture so we can confirm that.
• Do you have an Owners Manual? If not, I strongly advise getting one and read it to see if there are any more notes.
• Do you have access to parts diagrams? KubotaUSA.com gives access for us southerners, but I understand you northerners are locked out. There may be a Canadian version; you'll probably find it useful.
• Did the backhoe come from the same seller as the tractor? Either way, post pictures of the back of the tractor and front of the hoe so we can try to make sure you have the mounting needs.
• The tapped holes I see fasten the top of the console. Kubota also uses the top as a structural support; on my L35 I think it supports part of the joystick gimble, on yours I think it supported the swing sensor which is going away.
• Do you have an Owners Manual? If not, I strongly advise getting one and read it to see if there are any more notes.
• Do you have access to parts diagrams? KubotaUSA.com gives access for us southerners, but I understand you northerners are locked out. There may be a Canadian version; you'll probably find it useful.
• Did the backhoe come from the same seller as the tractor? Either way, post pictures of the back of the tractor and front of the hoe so we can try to make sure you have the mounting needs.
• The tapped holes I see fasten the top of the console. Kubota also uses the top as a structural support; on my L35 I think it supports part of the joystick gimble, on yours I think it supported the swing sensor which is going away.
-Here’s a photo of the hydraulic hoes loop at the back of the b20.
-yes I have a owners manual, been studying it.
-yes, I have access to part diagrams at my local kubota dealer. I have found it extremely useful.
- yes the backhoe did come from the seller of the tractor.
- the tapped holes fasten to the top of the console? Not seeing holes in the console, see photo. I believe the holes would be near between the operating stickers. ( this is quite bent.). i also have looked at the front of the casing around the hydraulics, but none match the distance of the tapped holes.
- the last two photos are those requested for backhoe attaching to tractor. Looks right to me.
-yes I have a owners manual, been studying it.
-yes, I have access to part diagrams at my local kubota dealer. I have found it extremely useful.
- yes the backhoe did come from the seller of the tractor.
- the tapped holes fasten to the top of the console? Not seeing holes in the console, see photo. I believe the holes would be near between the operating stickers. ( this is quite bent.). i also have looked at the front of the casing around the hydraulics, but none match the distance of the tapped holes.
- the last two photos are those requested for backhoe attaching to tractor. Looks right to me.
Attachments
Last edited:
Ken I have something that may be of interest to you. This section is part of an assembly I bought on eBay several years ago. It was advertised as new (which all evidence says is true) and possibly for a Hyster lift truck (which seems logical since it had one single-acting section and three double-acting sections, two with reliefs).• @TheOldHokie, the resident hydraulic guru, started a tutorial. You can get the basics here:
• I may have a lead on a section. eBay or similar. Husco dealer/distributor will be expensive.Kubota Hydraulic Info and Q/A
To the admins - if this is out of line or inappropriate please delete it. I am starting this thread to give folks a chance to learn the basics of Kubota tractor hydraulics. Its the number one topic here and multiple people have asked for something of this sort. Its an open discussion. Feel...www.orangetractortalks.com
• As I posted above, probably Gentec or Kubota for the mechanical parts. Let's keep that on a separate thread, especially with a change in plan on the valve. I don't think there's room in your console to add a section like RaleighL35 did.
Upstream face - this would face the inlet end fitting (left) that the pressure and tank hoses connect to, and which has an o-ring in it.
Downstream face - this faces the outlet end fitting, which in this installation just sends the fluid back, Husco calls it a turnaround. The small round thing just inside the o-ring on the left side is the load check; the poppet is there, but, alas, the spring is AWOL. This is why, when you disassemble one of these things, you need it on a clean bench with the outlet end up.
Caveats
• I can't be positive this is a standard parallel, double-acting valve, but I feel certain it is.
• It does have two port reliefs as you can see. I have no way of knowing what pressure they're set at.
• It has a tang on the spool end, not a clevis.
• I dropped the load check spring. If I find it, it's included; if not you can reuse your old one.
If interested, PM me (OTT calls them conversations).
@North Idaho Wolfman, if this needs to be handled another way, please let us know how.
Thanks, I can see that the hose is looped. My main concern is that the hooks, etc on the tractor and the pins on the backhoe are accounted for. You probably also need the backhoe Operator Manual (mine is separate) to show how they mate.
I'm not sure what that is on the 3ph, but I think the lower arms have to come off before the hoe goes on. Again, the manual will tell you.
There may be a missing part that uses those holes. This is where the parts diagrams come in handy.
I’ll look into it. Yes it's missing two cam devise/Pins I'll check with dealer for availability. Good eye!
Last edited:
The spring has been found. The only two loose parts on these sections are the spring and poppet.
Great! I’ll begin opening up the backhoe this week, when I’ll be more understanding as to how this all goes together.
I’ve started removing all electrical components of the auto return in preparation for removing the spool to make sure everything is ready to receive the new part you have. A few questions If I may?
- this linkage attached to the front two levers has 3 red wires going to it. I’m assuming I should remove it as well? See. 3 photos. The 3rd phot is looking from the front.
Attachments
These next photos are where the electrical auto return routes to the bucket/ boom . I believe all this can be removed as well? Correct? See photos taken below where the operators feet are above. The second photo shows the wire more clearly.
Attachments
Last edited:
Yes, the new configuration will have nothing electrical. Remember to take pictures and keep all parts you remove.
That's the position sensor hardware. It can all be removed. The new position sensor will be the operator's eyeballs.
I’m wondering if once I replace the far right section of this spool with a manual section ( offered previously n this thread, not sure if im use ing the correct terminology) if I’d have all the parts needed. It seams to me that the right lever need to be connected to the last hydrolic spool section somehow as I looked at one that was converted to manual on a Facebook b20 group. I’d like to post tat image for you all but I don’t know how to transfer a video off of Facebook and place here. I hope this post is clear enough.
Attachments
I watched the FB video you referenced. It doesn't tell anything about how the conversion was done, but it shows about how yours will look when we're finished. I'm posting a screenshot from that video below.
• Highlighted is blue is the 'connection' that I think you referred to above, and that you called a 'cylindrical device' on the PM. This is the linkage I've mentioned several times that you will need to fabricate/modify to connect the joystick to the valve spool. It will resemble the one on the other end of the stack. You can see, if not in this screenshot more clearly in the video, that their new section has a clevis or fork end on it where the section I've offered has a tang and will require a fork on the mating link.
• Highlighted in yellow on the section next to the end is a work port relief that I've mentioned previously. There is also one on the bottom of the section for the other port. The new section in the video has no port reliefs, while the one I've offered has two. Kubota commonly puts reliefs on the swing, I suspect the solenoid section wasn't offered with reliefs from Husco.
• It would be interesting if you asked the facebook author where he procured that section. The one near the inlet end of the stack is, theoretically, available from Kubota for ~$1,000, without reliefs, or ~$1,200 with reliefs.
This is getting long so I'll make one or two more separate posts.
1. Mark those hoses and connections before you remove any more hoses.
2. Let me review the status of things before you remove the valve.
Later
Great! Yes, you’ve correctly understood my previous laypersons explanations. Way to have strong detective ability! And thank you for your patience. I’m starting to understand. I’m working slowly as I’m in full swing harvest so not a lot of time for these fun projects.
Last edited:
OK. What are you harvesting BTW, if you don't mind me asking? Down here in the mid-south US, cotton picking is about to wrap up. Corn and early soybeans were a couple of months ago, as I recall. Wheat beans, planted after winter wheat if grown, are about ready. Those are the big 3. Vardaman, Ms, which calls itself the "Sweet Potato Capitol of the World", is about 50 miles south of my Ms place. About a month ago when I was down there, I saw a bus loaded with what I suspected was workers. A few days later I saw a truck loaded with sweet potatoes in crates, headed for Vardaman I'd guess. Support Ms, eat more yams! Now back to business; I'm surprised you've dedicated this much effort to this.
I don't know what information is available on the Canadian site. There is a BT750C version for the B20 (as well as 2 versions of the -B, if you weren't aware). The -C appears to be a -B without the auto return. That's where I got the section prices I posted earlier, BTW. So, theoretically, we're converting your -B to a -C; although I haven't compared any part numbers and have no way to know for sure if they're interchangeable. With that said, I'm going to use the BT750C parts figure to explain the linkage needed.
Heck, this is almost too easy. You'll need to duplicate, mirrored, part 010 to be like 020. Weld that peg on the side, I think you stated you're a welder. Instead of a groove to hold a cir-clip, I'd just drill it for a cotter pin. The rod end 060 is less than $20 from Kubota, so I'd use it. Rod 2, 090, is $75!, and won't work with the tang valve anyway. I think that the threads in 060 are 3/8"-24. Buy a 3/8" NF bolt, cut the head off to the appropriate length, cut a notch to straddle the tang, and drill a hole for the pin 110. Round the end of the bolt so it can swivel around the tang without binding. If you're feeling flush, you can buy 110 from Kubota for $12+ ea. I see screws and nuts on some of your sections. I drilled cotter pin holes in a nail for mine.
If you use a section with a clevis, you'll need to cut/grind the end into a tang instead of a fork.