Loader GC2310 hydraulic issues...again!

[oldnslo]

oldnslo,
The excess flow line is the manifold that sits at the top of the main control valve assembly. It is held down by 2 small long metric bolts (possibly 5mm) The manifold has two metal lines coming from it. They go out under your right foot to a block. Connected to them is one line that goes to the pressure port on the loader valve assembly, the other line goes to the T port on the loader valve which if I am correct and looking at the hydraulic schematic, that was provided by another member, is the transmission return line. If I remove that manifold I get no flow from the pressure line, which is the same if I remove the other end of the line at the pressure port of the loader valve. If I put a pressure gauge on the test port I get near zero( 100 psi maybe?) until I operate the steering wheel then it jumps to 1200 psi.

If no flow at the excess flow port then the problem is upstream between the priority flow valve and that manifold port. I would expect minimal pressure on the test port since it would only be showing line losses and charge pressure when no other functions are being used.

Maybe look at where that excess flow block is mounted. If both pressure and tank are in that block is there a drill path that could connect them both in the main mating block?

Hopefully not chasing a thin casting wall or drill wondered that created a thin wall that fatigued and broke connecting pressure to tank. Chased that problem on some manifolds years ago and am sure have either more gray hair or less hair thanks to that.

I have a long hydraulic hose that has a slow drip. I am thinking next time I am onsite I might try putting it on the power steering source port, run it under the tractor and plumb it into the loader pressure port and see what I get for pressure and see if the loader valves are working ok. If that works I'll try connecting the BH up and see if that all works ok.

Great idea, my suspicion is the loader will work just slower. Lets see if proven wrong…

At this time I did buy a used Main Hydraulic Control Valve Assembly (I think you sent me the link) for $400 plus tax. I was hoping it would be here by Set 25th but the tracking I got says Sept 26th which isn"t good for me. We are getting our camper ready to move to a new campground and the gentleman moving it says he might want to move it Friday Sept 26th. Anyhow, I do have the main hydraulic control assembly off the tractor so I may need to put it back on this weekend to 1)See if I fixed the problem by removing it and disassembling and cleaning every port and device attached to it or 2)Try connecting a hose the the power steering port and loader valve to see if I get get some pressure to the loader and test the loader that way. Does all that make sense?

Oh, and I did put a brand new flow divider valve on the main hydraulic assembly and it did not resolve the issue.

Thanks for listening to me!

 

[Dmacleo]

Good post. I don't know much about hydraulics and pressure but I am learning as I go. I was hoping this was going to be my issue after speaking with a service tech at a local dealer. But of course no such luck. He suggested the BH connections because it was the last hydraulic valve that was operated before it quit. Still trudging along. Stay with me and maybe we will both learn something.

I was wondering about BH not really due to valve but hose damage on the 2 that connect together with BH removed due to possible drag damage while loading onto trailer. never had that stop fel fully but have had it drastically affect it while BH itself zero operation.

 

[oldnslo]

The back hoe valve and connections should have minimal affect on loader operation since loader is typically the first valve in the circuit. It will potentially prevent the 3 point from working.

If back hoe is connected incorrectly you could dead head the pump forcing all of the oil over system relief but loader should still work unless loader valve is a series / parallel style where flow from lift cylinders is fed into power beyond to feed tilt cylinders. Kubota used to and may still have that feature. Not sure on your MF though.

Either way you should pressure at loader valve even if back hoe is connected wrong.

 

[Bentrim]

While I was working (retired due to medical issues) I used to put loaders on the GC 2300 tractors.
Early tractors you took a three bolt cover off the right side of the top cover, Installed a plate with places to put hoses in. One hose went to the loader and the other returned the oil back thru the adapter to the three point hitch valve and one returned oil to sump.
Later tractors the hydraulic lines were run up under the RH floor board. There was a U shaped tube that you removed and put couplers and hoses to.
We never installed a backhoe as they only came installed from the factory. but I do remember three hoses to the hoe Theyn had couplers and were marked with colored zip ties. One was pressure, one returned oil to thr three point valve and the other went to sump.

You might want to check the couplers to be sure the aren' partially apart. Does the engine pull down or does the relief valve squeal when the engines running? Might want to loosen the lines on the tractor side of the lines under the RH floorboard.

Wth the diagram you included do you have any oil at the output of the pump or the inlet of the valve? You should because you have steering. Have you checked the suction scrren in the rear housing. If the pump can't get enough oil it may not be more than the steering needs. Or if the relief valve is open it cannot make pressure. Do you get flow out of the pressure line to the loader valve?

 

[Dmacleo]

wondering if loader and hoe have been physically removed and out of way. pressure gage on loader connections can be used to test. 3pt will not work at all with hoe attached. arms can't drop so can't really see if working. and lift may not be able to be heard when hits bypass (full rise) due to engine noise.
simplify everything, get all attachments off, hook your 2 hoe hoses together then test stuff.

 

[Bentrim]

Flow is Pump to priorty valve steering has priority after steering is supplied then flows to the loader valve. Loader valve to backhoe valve then to the three point hitch. Flow to loader comes from the pipe under the right floorboard and the power beyond is hooked to the return pipe. If tractor is not equiped with a loader the is a U shaped pipe that hooks those two pipes together to prvide flow to the hitch. The return port from the loader returns to sump. The power beyond flow goes to the BH pressure port. Yhe power beyond from the backhoe goes to the three point. The return port from the backhoe is to sump. If the backhoe is removed the supply hose to the backhoe must be connected to the hose that goes to the three point valve. If you connect wrong you may be returning the oil to the sump and none to the hitch valve. One hose, The one to the sump will be disconnected with the hoe off.
If you have no flow to the loader you have an issue with the pump, priority valve, or quick couplers.