MF202 Workbull Backhoe Hydraulics

Hello all,

Everytime i have a question my google searches lead me here so I finally created an account haha.

I have aquired my neighbors 202 industrial workbull, after dragging it out of its resting place in the woods for the past 15 years and brought it back to life.

My neighbor beleives this particular unit orignally came equipped with a backhoe, as the loader frame protrudes rearward past the rear axle and had a series of holes that very well may have been the mount. So the otherday after chasing around a davis 185 or similar baclhoe to no prevail, i got a Universal Industries UH800 backhoe. Its a 3 point backhoe that looks to be of similar size to the original unit.

This backhoe currently plugs into the hydraulics on the tractor through the universal couplers that all newer tractors have. My tractor however, does not have an auxillary hydraulic valve or connector.

so my first solution was to simply get a PTO driven pump and resevoir. and then i came across a tisco part that is a "hydraulic isolator valve" that diverts the internal pump for the 3 point to be used for an auxillary circuit. So i ordered that. It hasnt arrived yet and i was discussing this with my neighbor and he said that the backhoe was ran off the same hydraulic manifold that the loader hydraulics are, powered by the front pump, and simply plumbed to some ports on the bottom of the loader control block. I see ports that appear to be currently plugged with fittings.

my question is, to run the backhoe unit efficiently and effectively, should I / could I use the loader hydraulics as suggested by my neighbor? Or i read on a similar topic that that pump was only suitable for the loader and that it will burn it out to use it for other things? Or would i be better off using the internal pump for the 3 point system? And would one or the other work better based on pressure or flow ratings of each pump? And if anyone has any info on which ports on the loader control valves do what exactly, that would be a huge help as well. I havent been able to find any pictures or info really at all about the plumbing for the backhoe or similar.

Thank you in advance for any and all help,
Peter

According to Tractor Data, that tractor has a 4 GPM, 2800 PSI hydraulic system designed for open center valves.

That sounds like too low GPM to operate a back hoe of any size.

Need to get with the back hoe supplier to see what their requirements are.

I don't see any way to operate a back hoe with open center valves. Think you would need a variable displacement pump so you can use a closed center system, which means it would need to be driven off the engine.

Others may have another solution...

if your workbull is same as mine was, you have a front pump running the loader, loader might be a 100 or 200 MF or Davis, front pump moves about 18 GPM at around 2000 psi depending on how worn the pump is

the backhoe would have run off a pressure line coming off a special fitting on underside of the loader valve, oil return was to an elbow fitting on right side loader frame

when they took the backhoe off, maybe they removed that special fitting on the loader valve and replaced it with a loader only fitting, in that case the unused oil returns to loader frame from inside the loader valve

unless you have tiny pistons on that backhoe, the internal hydraulic pump will be glacial

Thanks for the quick responses, i figured that would be the case with the internal pump based on how slow the 3 point arms lift to begin with.

So it sounds like i should find out what i need for fittings to hook it up to the front pump at the loader controls. The cylinders on this unit arent all that big and im just planning on digging small stuff, and my ground is really sandy so i dont think underpowering it should be an issue. Worst come to worse i can pick up a pto pump if just cant do it. Or else simply build in an accumulator and intensifier into the system for a small burst of America Power when i need it.

I already built a 2 blade drag land and gravel scraper/leveler/grader this weekend for the driveway, next im thinking i need to build a bagger 288 style trenching sawblade.

Lots of oc systems, basically the 'original'-most common of the older era. Type of equipment, ;ie backhoe, doesn't matter, it's the control (valves) & pump that make oc or cc. I'm remembering the work-bull as oc, separate loader/hoe system. I know some people here have/had one, probably easiest to look at one and check what goes where. Unfortunately the one here got a new home 3-4 months back so can't look/take pictures.

Okay so more development, after cleaning the grease and such off the control valve i can see that it has cast labels on the top for the ports for the loader, bucket, boom, etc. And on the bottom of the valve there is a large port that is currently plugged with a plug fitting that is 1 1/2 inch across the flats, which if it is an ORB fitting, means it is an 1 5/16 SAE ORB. And this particular port is labeled "BEYOND" so im going to assume, which ive heard is a very dangerous word, that this is the supply line to the original backhoe unit.

The only thing i cant figure out is where the return port is. If it just tee's into the elbow that comes out of the tank to the pump, or if theres a return port somewhere.

I apologize for my clumsy postings, i am attempting to upload multiple pictures i took but am having difficulty doing so from my phone, i will try from my computer later.

That looks like a different valve than what was originally on my 202. I guess it depends on which loader it has on it. Mine has a Davis 102 loader and a Davis 220 backhoe which is likely what yours was set up with originally. Underneath the control valves and on the outside of the loader frame there is a plunger type valve which you pull outward to engage the backhoe and push back in to operate the loader. I'll see what I can find for pictures to upload.

It wouldnt tee into the outlet line that is the sump to go to the pump, i realize after reading what i typed how silly that sounds. i suppose i could just "add" a return to tank port on the tank but would need to do it as to keep the shavings contained.

Also just for reference the tag says Massey Ferguson model 100 loader. which i realize is Davis or whatnot.

Also the last picture attached is one i found on another thread on here, i can see the line going rearward from what looks to be the exact same valve as mine.

UPDATE:

Okay after some more research i am realizing that i need a specific "power beyond spool" adapter plug thing, not just simply a fitting to connect to the port.

Is there any guru out there that might be able to tell me what valve number i have or better yet what power beyond adapter i need? I will try to find the specific casting number on my valve when i get home from work.

As far as finding original parts, unlikely. The return lines dump directly back into the loader arm thru the control valve. I built an adapter plate for mine and put a more modern set of controls on it. I needed parts for mine and there were none to be found.

I'd like to upload some photos for you but for some silly reason I can't seem to. I think it might be a McAfee thing.........

go to Agco parts books as guest, browse the books, under material handling/mounted loaders you will find 100 loader plus others

under control valve I found this:

705372M91 1 Plug Assembly (Replaces Item 35 When Back Hoe Is Used)

however, finding one at a dealer is probably not going to happen

good luck

This is from the bottom looking up at the area where the original control valve was mounted. I made up a plate to which I could attach the return line. I built my own hydrostatic steering which also uses the front hyd. pump so that will be any extra smaller plumbing you see there. You can also see the valve which changes the flow to the backhoe. There are quick disconnects for the backhoe lines. You can actually have the backhoe off in 10-20 minutes once you've done it a couple times. I'll upload some more pics when I'm home from work, just wanted to make sure I had my picture uploading problem fixed.

Wow thank you, I wish i would have known about those catalogs a long time ago, after looking at the system some more, my neighbor and I have decided to add a diverting selector valve upstream of the loader control valve that will divert the flow to the axillary circuit most likely to later have a true SCV added in for rear hydraulics controllable from the operators station, rather than trying to track down one of those power beyond plugs.

Since i already bought the TS300 "isolator" valve to use the internal hydraulics, i'm going to set those up as well, and just use that circuit for low demand circuits. The standpipe came up with the cover when i removed it but i think i got it seated back where it needs to be. Fingers crossed.

Thanks for everyones help and input.
-Peter