B26 lacking lifting power

[patiobob]

I bought a b26 and it will easily pick machine off the ground using the bucket and hoe stabilizers, even at idle, but when I go to actually move a pile of dirt at operating RPM the machine struggles. It is also dumping and curling the bucket very slowly. It has to be a simple adjustment, but I can't see how to do it. I've owned b20 and b21 in the past and never had this issue. This machine has some sort of integrated control valve for the loader that I don't know how to adjust. I don't think I need more pressure, I just need more flow, or relief valve not to activate. It does sort of sound like the relief valve is releasing pressure when I dump or curl bucket and it moves fairly slow compared to my b21 (which I still own and has more lifting power than this b26 currently) I took the caps off the end of the loader control valves, and there is a spring in there, but I don't see any adjustment. There is not a ton of room in there either to see. Once I took the caps off the loader arms would drop with the slightest movement of the joystick control, but still seemed to go up slowly. Do the caps themselves need to be shimmed? Thanks in advance for the help.

 

[dirtydeed]

I bought a b26 and it will easily pick machine off the ground using the bucket and hoe stabilizers, even at idle, but when I go to actually move a pile of dirt at operating RPM the machine struggles. It is also dumping and curling the bucket very slowly. It has to be a simple adjustment, but I can't see how to do it. I've owned b20 and b21 in the past and never had this issue. This machine has some sort of integrated control valve for the loader that I don't know how to adjust. I don't think I need more pressure, I just need more flow, or relief valve not to activate. It does sort of sound like the relief valve is releasing pressure when I dump or curl bucket and it moves fairly slow compared to my b21 (which I still own and has more lifting power than this b26 currently) I took the caps off the end of the loader control valves, and there is a spring in there, but I don't see any adjustment. There is not a ton of room in there either to see. Once I took the caps off the loader arms would drop with the slightest movement of the joystick control, but still seemed to go up slowly. Do the caps themselves need to be shimmed? Thanks in advance for the help.

No. That is not how the relief pressure is adjusted. The relief valve is located near the right rear wheel. I'd suggest downloading the workshop manual. Have you checked the hydraulic oil level and disconnected/reconnected all hydraulic lines (loader and backhoe)? You could possibly have a slightly disconnected fitting.

After that, get yourself (or fab) a hydraulic pressure gauge to see what your actual pressure is. If its low, you can buy shims for increasing the hydraulic pressure if that turns out to be the cause.

maybe start by looking at this thread...

B26 TLB Hydraulic Pressure Check

As anybody done a hyd. pressure check on a B26. I'm wanting to check it because dealer states nothing wrong with hydraulic system. It's brand new with 77 hrs. 4n1 bucket kubota 3rd function and hydraulic thumb. I been stating since new something wrong because hydraulic as no power. Backhoe is...

www.orangetractortalks.com

 

[patiobob]

No. That is not how the relief pressure is adjusted. The relief valve is located near the right rear wheel. I'd suggest downloading the workshop manual. Have you checked the hydraulic oil level and disconnected/reconnected all hydraulic lines (loader and backhoe)? You could possibly have a slightly disconnected fitting.

After that, get yourself (or fab) a hydraulic pressure gauge to see what your actual pressure is. If its low, you can buy shims for increasing the hydraulic pressure if that turns out to be the cause.

maybe start by looking at this thread...

B26 TLB Hydraulic Pressure Check

As anybody done a hyd. pressure check on a B26. I'm wanting to check it because dealer states nothing wrong with hydraulic system. It's brand new with 77 hrs. 4n1 bucket kubota 3rd function and hydraulic thumb. I been stating since new something wrong because hydraulic as no power. Backhoe is...

www.orangetractortalks.com

I'm confident it is not a pressure issue. The loader arms go up and down well. I don't have the machine for long, have not even put fuel in it yet. It is a bucket curl circuit issue. I almost wonder if the seals aren't bad in that half of the circuit. Those caps on the bottom seem to hold most of the mechanism together. Looking at the diagram there might me one set screw and then the linkage you have to remove to slide the whole thing out. I just checked all the lines, no kinks. You can put your hand on the bucket circuit line as it enters the control valve and feel the vibration and hear it. It does almost sound like pump is missing fluid, but machine is full, and it only does it with curl, not loader arms. Fluid somehow not flowing properly. I was guessing it was bypassing. I did clean the two check valves.

 

[je1279]

Did you disconnect and reconnect both of the curl hoses?

 

[Smokeydog]

Did you disconnect and reconnect both of the curl hoses?

B26 loaders do not come off the tractors like the ag tractors.

The valve is not at the joystick like my B20 was.
The B26 has considerable more lifting power than the B20.

The B26 do have design problem on the suction side of hydraulic pump rubber elbow cracking letting in unfiltered air. They make an update hard and rubber line to fix this issue.

Do the easy stuff first. Since you bought used, change the fluid and filters. Use kubota filters and super UDT. Be a good time to inspect and replace that elbow with the fluid drained. I could not see the cracks until I removed. Right side of engine. If you change to new suction line assembly you have to remove the right rear wheel. Cost was the same as the old rubber elbow.
Still a problem?

With the wheel removed you can see the loader control valve. There is some cable linkage that might need adjustment to get the valves to fully open for the curl.
I would caution any work done without a shop manual.

 

[patiobob]

B26 loaders do not come off the tractors like the ag tractors.

The valve is not at the joystick like my B20 was.
The B26 has considerable more lifting power than the B20.

The B26 do have design problem on the suction side of hydraulic pump rubber elbow cracking letting in unfiltered air. They make an update hard and rubber line to fix this issue.

Do the easy stuff first. Since you bought used, change the fluid and filters. Use kubota filters and super UDT. Be a good time to inspect and replace that elbow with the fluid drained. I could not see the cracks until I removed. Right side of engine. If you change to new suction line assembly you have to remove the right rear wheel. Cost was the same as the old rubber elbow.
Still a problem?

With the wheel removed you can see the loader control valve. There is some cable linkage that might need adjustment to get the valves to fully open for the curl.
I would caution any work done without a shop manual.

Thanks, I'm more and more confident it is only 1/2 of the integrated valve system. I did actually read something about that rubber boot and tightened mine. I suspect it was getting a small amount of air in there, as the hold down clamp bolts were fairly loose. It didn't fix the bucket problem, but I am taking possibilities off the list. It did seem to fix a slight whine at start up though. Loader arms go up and down perfectly fine, no noise, hiss, or whine. Only the bucket circuit, both dump and curl both whines and is quite slow. RPM makes no difference either. I'm leaning more toward that control valve needing new seals. The hydraulics seem fine and I have owned many machines (7 at this moment alone), so I'm not inexperienced with the sound and feel of a properly working system vs one with an issue. I'm not familiar with the b26 setup of the loader control valves specifically. The hoe would be an easy fix, but these particular valves are basically built in to the system. That is the thing, the hoe works fine also, so it is just the one valve spool/circuit on the entire machine that I seem to be having an issue with.

 

[kubotafreak]

Play with the 3 point to make sure your not in overload for the rockshaft.