Quickie loader, very slow. WHY?

[rScotty]

I may have found us a usable Work Shop Manual (WSM)... it's for the M4900/M5900 - the model right after yours. But it sure looks like the same hydraulic layout. Take a look and see what you think.

If so, then your hydraulic pump on your tractor and the M5900 are a piggyback dual (3pt hyd+PwrSteering) type and so there will not be a power steering priority valve in the hydraulic circuit. With a piggyback pump The PS is already completely a stand-alone circuit as it should be.

Ant that also means that the main hydrualic in a bacic M5400/M5900 unmodified tractor could be run directly back to the rear - which also seems to match this WSM.

I've got some other thoughts, but first take a look at this WSM and see what you think. The search function doesn't seem to work for me. The hydraulic section of the WSM is section 8, approx pgs 334 to 353.
rScotty

You can find the manual at:

Index of Kubotabooks/Tractor Owners Manuals/

 

[jahmes143]

@rScotty I think it's the exact same setup. In fact, the hydraulic cylinder is the exact same part number for the M5400 and the M4900/M5700.

 

[Gordon Gould]

The photos are great! Now we can make some educated guesses, but because yours has power steering we probably still need the hydraulic schematic in the workshop manual for the Kubota M5400, do you have that manual? I will look for one

1st Photo:
Line 1 is the "P" or pressure line coming either from the hydraulic pump...OR from one side of a priority valve that separates the main hydraulic pump flow into a power steering flow that has priority and then the remaining flow goes to everything else. Line 1 comes from rockshaft cylinder
Line 2 is the return to the "T" sump or Tank.
Line 3 is the power beyond that goes back to the 3pt. If we could see the side of the valve casting there should be a raised "PB" there. You should trace all these lines to confirm. There is a P and a T on the casting for lines 1 and 2, but no casing markings for line 3

NOTE: IF LINES 1 & 3 ARE REVERSED into the Control valve, that could cause the loader to be slow. So be sure to trace those lines!

2nd Photo. Not sure what view this is. What are we looking at? Lines 1 and 3 where they terminate into the rockshaft cylinder.

3rd Photo. From underneath? #2 should be going to the tank sump, but is it? I see some splits in that old hose where it bends, but if it is return to tank, those don't matter. Yes, from underneath looking up. I do believe it's going to tank sump. Splits in hose are not leaking, but will replace hose in near future.
Is the steel line the suction line from sump tank to your filter? Yes
What is the unnumbered hose? Actually 2 hoses there (one above the other), hoses 1 and 3 going to/from the rockshaft and control valve.

Now we are getting somewhere.

I should stay out of this. jah-- is getting good help and doesn't need more to confuse things. But just a comment/question - When he said Line 1 (P-in) incomes from the rock shaft cylinder and not the pump, to me that sounds suspicious. Shouldn't it come from the pump or a hydraulic block at the pump outlet ??

gg

 

[rScotty]

@rScotty I think it's the exact same setup. In fact, the hydraulic cylinder is the exact same part number for the M5400 and the M4900/M5700.

Well good. You may have just saved the cost of the gauges kit.

I wish we had the equivalent install manual from Quickie Loaders just to make sure that the hookups the prev. owner did are correct. I'm beginning to wonder if the loader ever did go normal speed.
The speed the loader moves is roughly what one would suspect if the cylinders were responding to the differential between two opposing pressure flows.

The WSM shows that the PTO on/off valve is hydraulic, but is powered off of the power steering circuit, so it is not the culprit.

It's also interesting that the two hydraulic filters are in parallel....A better idea brought to us from the:
Department of Redundancy Department

rScotty

 

[rScotty]

I should stay out of this. jah-- is getting good help and doesn't need more to confuse things. But just a comment/question - When he said Line 1 (P-in) incomes from the rock shaft cylinder and not the pump, to me that sounds suspicious. Shouldn't it come from the pump or a hydraulic block at the pump outlet ??

gg

Glad to have you. The more the better. If you download that Workshop manual WSM and look at the schematic about page 316 or maybe 332 .... and also at one of the very last pages...then...

You will see that the hydraulic pump output only goes one place - which is directly back to the rear casting in the area of the rockshaft. Also back there in that area are some poorly defined accessory hydraulic outlets labeled A & B - but just how they work is a bit of a mystery only partly explained on a page at the very end of the WSM. My guess is that there is a lever or adjustment or something that causes either A or B to become a Power Beyond port to feed pressure forward to the FEL....but that doesn't quite fit with what we see on the FEL valve photo.

So I'm also wondering if there is a mistake in the plumbing or instructions from the Quickie Loader or in which control valve they provided. And if so, It may have been that the FEL was always that slow.

But we are closer. At least we understand a bit more of how it works. And can dismiss the power steering and PTO valve.

rScotty

 

[rScotty]

We ought to check the obvious. Could it be that the control cables that work the spool valves in the FEL control valve are just not pulling the valves open fully?
Can you check that?

 

[jahmes143]

@rScotty I checked the cables (exposed them and manually pulled them to their limit) and they appear to be functioning properly. I found the attached. I have the Commercial Hydraulic valve referenced on p20. Not sure if this is helpful.

I was also able to find the attached screengrab from a Quickie 310 manual. Manual stated control valves will vary based on particular tractor model.

 

[rScotty]

@rScotty I checked the cables (exposed them and manually pulled them to their limit) and they appear to be functioning properly. I found the attached. I have the Commercial Hydraulic valve referenced on p20. Not sure if this is helpful.

I was also able to find the attached screengrab from a Quickie 310 manual. Manual stated control valves will vary based on particular tractor model.

 

[rScotty]

I'm not surprised that you checked the cables. Now wecan dismiss that possibility.

I wonder what that Hydraulic Valve on page 20 is doing in your circuit?
It is a soleoid actuated diverter valve that switches pressure between two circuits in response to an electrical current. That is, it switches two circuits depending on whether the solenoid is resting or actuated.
My first guess isit could replace the manual levers for the A & B accessort ports.

What does it appear to be doing? Trace the hoses?

The screen grab would be very helpful, but the resolution is too low. Can we get better resolution?

 

[jahmes143]

I don't know what that Hydraulic Control Valve on p20 is, or if my unit actually has it. I don't think it does. Unfortunately, the screen grab is as high of quality as I could find from a circa 1998 manual. Frankly I'm to the point where I think I'll just take it to the Kubota dealer and have them fix the issue. After doing my due diligence, I'm not afraid to admit when I'm over my head!