Hydraulic arms not moving?

[kubotanewbie]

Greetings - my first post here.

My tractor is an older model of Kubota (8200HST) with loader & backhoe.

I'm preparing to temporarily replace the backhoe with few other attachments I ordered and I'm not quite clear on the rear hydraulics.

The hydraulic arms (in the attached photo) don't seem to be moving when I move the "hydraulic control lever" located to the right of the seat.

I'm not sure the back end of this tractor was ever used for anything other than the backhoe (which works fine), but I have the lifting rod & lower links for it, so I figured everything should work.

Are things magically going to start working once I remove the backhoe and attached a plow for example or is there something I need to change first?

I'd expect that by moving the hydraulics control lever located next to the seat I could observe the hydraulics arms move up & down.

Am I missing something obvious?

Thank you!

 

[irvingj]

Yep, I'm a newbie, too, but here are some thoughts:

Well, it looks like the 3PH arms are in the down position.... Does the hydraulic system make any noise when you attempt to raise them? If they're "frozen" you should probably hear some squealing as the system attempts to lift, I'd think.

Failing that, I know you can "lock" the arms in the up position... but is the lock on the floor (probably a knob) screwed all the way in to the lock position? Don't know if that would interfere with raising or not, but possibly.

And, yes, at least on my tractor, IIRC, I think the hose connections to the backhoe need to be removed & reconnected (with a return line) so the 3PH will operate. This sounds most likely. Hard to remember now; I leave the BH on all winter for ballast when snowblowing, and the only time I use the 3PH is to control the mid-mount mower deck-- with the BH off. I'm just not remembering if the 3PH and BH are mutually exclusive....

No manual? They're great to have around; perhaps you could get one from the big K. Hope this helps!

 

[kenstrac]

Disconnecting the backhoe will have no effect on tractor hyd. since the backhoe has it's own pump.
does the tractor have a loader and if so is that working?

 

[anojones]

One of the hydraulic experts will chime in, but doesn't a backhoe need a "power beyond" which bypasses the 3 point hydraulics- thus unhooking the backhoe will allow for the 3 point to work.

 

[kenstrac]

One of the hydraulic experts will chime in, but doesn't a backhoe need a "power beyond" which bypasses the 3 point hydraulics- thus unhooking the backhoe will allow for the 3 point to work.

Well thank you, I guess my observations that the backhoe is self contained and has nothing to do with the tractor hydraulics is mute and does not make me an expert. Maybe JJ can chime in and give the same answer since my skills ain't worth a rats *****

 

[MarEng]

There are two arrangements (that I've seen) for 3-pt backhoes. One uses the PTO to drive a separate pump mounted on the BH. The other (ours) uses the tractor's pump. When I remove the BH I take the pressure line to the BH and reconnect it to the 3-pt arms - look for a loose hose floating around back there with a quick connect on it that matches the end of your BH pressure hose. Once this is done the 3-pt begins working. The return line that connected to the BH now floats around collecting dirt and debris. I usually plastic bag and duct tape (the handy man's secret weapon) whichever end is floating around at the moment to try to keep it clean.

I did have a problem the first time I removed the BH (two years after purchase). No pressure/3-pt movement. I changed all of the filters. Nothing. Off to the shop. The hydraulic filter base was found to be plugged with trash. I suspect there was a leg of trash in the return line that blew out the first time it was connected and overwhelmed the filter. Took somebody with gages and some know how about 15 minutes to find it and another 15 minutes to pull the filter base and clean it.

 

[Kernopelli]

I agree with kenstrac, it appears your BH has a PTO pump so it uses a separate hydraulic system from the tractor so the BH should not make a difference. I am not familiar with your tractor whatsoever but I would first make certain that you are using the correct control valve and not a lever for something else like a draft control. Then I would check to make sure that all linkages are attached to the control valve as far as you can trace them. Check anything that may lock out the rockshaft ("hydraulic arms") function as was mentioned by irvingj. We are assuming that your pump is working (I don't know if your tractor uses a separate pump for the HST but suspect it might). Does the tractor have a front loader and if so does it work correctly?Do you have a manual? If so, this would be a good place to check for any hints as to what to look for. If all of these things work, it could be a relief valve that is stuck open or a piece of debris in the control valve. This makes things a little more complicated so start with the basics and let us know what you find.

 

[kenstrac]

I agree with kenstrac, it appears your BH has a PTO pump so it uses a separate hydraulic system from the tractor so the BH should not make a difference. I am not familiar with your tractor whatsoever but I would first make certain that you are using the correct control valve and not a lever for something else like a draft control. Then I would check to make sure that all linkages are attached to the control valve as far as you can trace them. Check anything that may lock out the rockshaft ("hydraulic arms") function as was mentioned by irvingj. We are assuming that your pump is working (I don't know if your tractor uses a separate pump for the HST but suspect it might). Does the tractor have a front loader and if so does it work correctly?Do you have a manual? If so, this would be a good place to check for any hints as to what to look for. If all of these things work, it could be a relief valve that is stuck open or a piece of debris in the control valve. This makes things a little more complicated so start with the basics and let us know what you find.

Thank you! I take it you looked at the photo and came to the same conclusion I did that it's a self contained backhoe.And the next thing is to find out if the loader works that would give some insight of what to trouble shoot next.

 

[Dead Horse]

If you have rear auxilary hydraulic connectors (with an actuator valve at the seat or some other location) such that the circuit is "open", your lift will not get pressure until you close the circuit.

 

[kubotanewbie]

Disconnecting the backhoe will have no effect on tractor hyd. since the backhoe has it's own pump.
does the tractor have a loader and if so is that working?

Yes, the tractor has a loader and that's working fine.