hydraulics nothing works

dabadas

New member

Equipment
kubota b26
Jan 18, 2016
20
0
0
Eden, N.C. USA
OK here I go again. I've changed the hydraulic fluid and filters. When i started it up it had air in it. Got the air out drove it around a while and seemed to be fine. so after sitting in my climate controlled shop for a few days I start it up and and it has air in it just from sitting. The steering was a little hard to turn to start with but now it is ok. The hst was ok too. the air seems to be in the front loader, backhoe and 3 point hitch side of the hydraulics. I'm heading back down to the shop to check the suction line from tank to pump. any ideas?
 

dabadas

New member

Equipment
kubota b26
Jan 18, 2016
20
0
0
Eden, N.C. USA
Checked the suction line, everything looks fine. On the rubber hose section the clamps seemed a little loose, so I tightened them a bit. I noticed when i get the front loader and backhoe to start working they seem slow. Also they are working at idle. But, when i increase the throttle they stop working.
 

North Idaho Wolfman

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L3450DT-GST, Woods FEL, B7100 HSD, FEL, 60" SB, 743 Bobcat with V2203, and more
Jun 9, 2013
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Sandpoint, ID
I would get a pressure gauge 0-3000 psi, and get ready to start testing.
Also this is a very good time to get the WSM (Work Shop Manual, AKA Service Manual).

Loose clamps on the suction line will cause some odd issues, so that may be part of your problem, and If they ran it a while with it having problems like that, you might need to have the pump rebuilt or replaced.
 

dabadas

New member

Equipment
kubota b26
Jan 18, 2016
20
0
0
Eden, N.C. USA
I have the repair manual. I took the rubber elbow off on the suction line and it appears to be ok (I ordered one anyway). So I put it back on and loosen the line at the cylinders to bleed off any air i could find. Took it out last night and used it everything worked fine. Come home from work today and same thing. Nothing works on hydraulic side. Steering is a little tight on the HST side but starts working after turning left and right a few times. Its not a little bit of air getting in, It is so much air the fluid gets foamy. I've got the O*ring and rubber elbow ordered for it guess Ill wait for them to come in and change them. Is there any where else it could be getting air in? I've changed the fluid and both filters (hydraulic and HST) and checked to make sure the old gasket came off and that they are tight. The O-ring should be below the fluid level of the tank, but I'm going to change it anyway. Thanks
 

North Idaho Wolfman

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L3450DT-GST, Woods FEL, B7100 HSD, FEL, 60" SB, 743 Bobcat with V2203, and more
Jun 9, 2013
29,223
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Sandpoint, ID
I would pull the whole line out and inspect for wear or a crack, and replace both the 90 hose and O-ring.
Also pull filter and make sure there is not an extra gasket stuck in there.

 

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kenmac

Member

Equipment
B26 with hyd. thumb and 4 in 1 loader bucket and EA Grapple, but not the wicked
Dec 14, 2015
92
7
8
Pell City, Al.
kenmac I'm not far from You either. Where abouts in PellCity do You live? I'm just over the mountain in Odenville.



You bought that tractor about 15 miles from My house. I too saw it on craigslist.
I'm in the thriving metropolis of Cook Springs. Howdy neighbor!
 

dabadas

New member

Equipment
kubota b26
Jan 18, 2016
20
0
0
Eden, N.C. USA
OK I have taken the the suction tube off and inspected it. I also replaced the o-ring and the rubber elbow with new hose clamps. I also removed the hyd. pump and disassembled it. Inspected every thing inside and put it back together. Bleed the air off it worked great. Lots of power. parked it over night and when I came home from work, I started it up and no hydraulics. the steering is a little tight until I turn it several times and get the air out. The HST works also. But nothing else work. Front loader, backhoe stabilizers or 3 point hitch. After it sits it loses its prime. Why? here no hydraulic oil leaking out from anywhere The hyd. pump has 2 sides. 1 for the HST and steering and 1 for the other hydraulics. the HST side does get some air but still works the other side nothing works till I bleed the pump to get the air out. Any ideas?
 

North Idaho Wolfman

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L3450DT-GST, Woods FEL, B7100 HSD, FEL, 60" SB, 743 Bobcat with V2203, and more
Jun 9, 2013
29,223
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Sandpoint, ID
When you pulled the line did you pull the filter and check for double gaskets or anything else to keep it from sealing?

Your next step is to send the pump to be tested, when they go bad they can cavitate and not create suction.
 

dabadas

New member

Equipment
kubota b26
Jan 18, 2016
20
0
0
Eden, N.C. USA
yes I changed both filters. I guess the pump is next. Is there a bypass in the filter bracket? It's posiable that it could be hung open. Thanks
 

100 td

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Equipment
B21TLB (B21, TL421 & BT751) Toyota SDK4 T116 Bobcat
Aug 29, 2015
1,776
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ɹǝpunuʍop
I bought a Kubota B26 and everything worked fine yesterday.....

The hydraulics was air locked.....

I've changed the hydraulic fluid and filters. When i started it up it had air in it.....

when i get the front loader and backhoe to start working they seem slow. Also they are working at idle. But, when i increase the throttle they stop working.

Took it out last night and used it everything worked fine. Come home from work today and same thing. Nothing works on hydraulic side. Steering is a little tight on the HST side but starts working after turning left and right a few times. Its not a little bit of air getting in, It is so much air the fluid gets foamy.

I also removed the hyd. pump and disassembled it. Inspected every thing inside and put it back together. Bleed the air off it worked great.
Lots of power. parked it over night and when I came home from work, I started it up and no hydraulics.
While I'm no expert, and am happy for anybody to correct me, it's difficult to diagnose from afar, without pressure gauges, and when you aren't the one doing the testing, alas, I offer the following.
Before sending the pump away, it appears the pump has worked on several occasions, so what is it about the pump that is stopping it from working?
Is it a flow restriction into the pump, is it a flow restriction out of the pump, is the pump sucking air, is there water in the system, is there a sticky relief valve, is there a faulty non return valve?

A couple of your statements have me thinking one way and that is ....

As mentioned previously, air getting into the pump is a likely cause, so I would recheck the oil filters, meaning screw them off, check gaskets and sealing surfaces and put them back.

However one of your statements has me thinking another way entirely
dabadas said:
when i get the front loader and backhoe to start working they seem slow. Also they are working at idle.But, when i increase the throttle they stop working.
This says to me the pump COULD be dead headed.
This creates heat and possible boiling of fluid and cavitation in the pump, and damage results. If this is occurring then you will have trouble each time you try to use the machine.
(However, it COULD also just be starved of fluid and be cavitating or sucking air with similar results, and as the transmission is affected as well, starving of fluid to the charge pump is a possibility.)

Dead heading could be caused in the hydraulic circuit in a couple of places I believe, try the following in the first instance.

If the backhoe hydraulic circuit is anything like it's little brother the B21, I would disconnect the backhoe hydraulic lines from the machine and connect them back together on the tractor to complete the hydraulic circuit, thereby bypassing the hoe altogether to remove it from the hydraulic circuit. Please ensure the hydraulic hose quick coupler is seated together completely.

Backhoe/3 point hitch selector lever - position the lever to deselect the backhoe, and if possible with a flashlight, watch the end of the shaft turn on the valve body when deselecting the backhoe to ensure correct operation of the valve.

3 Point Position control lever - ensure 3 point hitch lever is in the DOWN position, not the float position.

Make sure the 3 point hitch lowering knob is wound out counter clockwise.

FEL selecter valve - ensure the valve is centered correctly. If you have a 3rd function valve for 4 in 1 or similar, center it as well, or if it is electric remove the plugs from the solenoids if possible.

Check oil level with dipstick twice to ensure you get a correct reading and the oil level is within the specified range.

Remove hydraulic oil filler plug and leave it off altogether.

Start tractor and see how you go.
Remembering that due to the previous state of the tractor (possible pump cavitation or starvation), you may need to try to bleed air etc before seeing any change, if at all.

Further things to check, ensure the hydraulic tank breather pipes are clear, and possibly remove them from the transmission fittings to allow them to be open to the atmosphere for a test run.
 

100 td

Active member

Equipment
B21TLB (B21, TL421 & BT751) Toyota SDK4 T116 Bobcat
Aug 29, 2015
1,776
8
38
ɹǝpunuʍop
One other thing to check, not sure if the B26 has this, but many others do, ensure the hydraulic control screw is in the correct orientation, check your workshop manual, this is a pic of mine. Also if you have any quick disconnects on the FEL or on the hoses/lines supplying the FEL valve block, disconnect and reconnect each quick coupler to ensure they are fully seated home.
 

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dabadas

New member

Equipment
kubota b26
Jan 18, 2016
20
0
0
Eden, N.C. USA
ok sorry I've been away for a while. So I replaced the hydraulic pump and that fixed my problem with it losing its prime when sitting overnight. So far so good.