Kubota b2150 HST not working

[ruger1980]

No that is case drain to the reservoir. It is very low pressure. The filter is charge oil but I don't know if there are any taps there to connect a gauge.
If it were me I would probably use a modified banjo bolt in the line from the hydraulic outlet block to the filter housing to test. I have a bunch of them modified by drilling out the end and tapping to 1/8 npt for just this purpose.

 

[PoTreeBoy]

No that is case drain to the reservoir. It is very low pressure. The filter is charge oil but I don't know if there are any taps there to connect a gauge.
If it were me I would probably use a modified banjo bolt in the line from the hydraulic outlet block to the filter housing to test. I have a bunch of them modified by drilling out the end and tapping to 1/8 npt for just this purpose.

That sounds like a good plan. Since the power steering works there should be adequate flow to the hydrostat. The relief (back pressure) valve may not be providing enough charge pressure.

 

[Matoyan]

That sounds like a good plan. Since the power steering works there should be adequate flow to the hydrostat. The relief (back pressure) valve may not be providing enough charge pressure.

how would I test the relief valve or is that something that needs to be done at the dealership?

 

[PoTreeBoy]

how would I test the relief valve or is that something that needs to be done at the dealership?

how would I test the relief valve or is that something that needs to be done at the dealership?

You can do what @ruger1980 suggested in post #61. In an early post, I mentioned testing the pressure at the transmission, but it requires special fittings. What he suggests will accomplish the same thing. Any means of measuring the pressure in the line around the filter would work. It should have <100 psi at that point. Tee in, don't deadend it.

 

[Matoyan]

No that is case drain to the reservoir. It is very low pressure. The filter is charge oil but I don't know if there are any taps there to connect a gauge.
If it were me I would probably use a modified banjo bolt in the line from the hydraulic outlet block to the filter housing to test. I have a bunch of them modified by drilling out the end and tapping to 1/8 npt for just this purpose.

Could you post a picture of the modified bolt?

 

[ruger1980]

https://www.amazon.com/M12x1-25-Banjo-Bolt-System-M12-12MM/dp/B0BDK9F2H7/ref=sr_1_8?crid=3TZ4RARWBEUL8&dib=eyJ2IjoiMSJ9.hA1qX6NPefiwYAnjUDenGWUTN-N6lIDPQBTTQB9MwzYD0oUyoqHP_2-wQXGy5Zpq2764vLHD9BARBg2gfxC-ew2j_mcI-4CVHCy4no5z46UdFF_AWKg50dJacZbzd0-jhYGFT5zjdtmiEwY9HeawGw80e_TJyGZH-MJSu87jG7IW4qb5_lZM_u89eLRuP1ltA4TtzbaykGOEC6W9Tlr65kTbFcJXpLBUu-7R9YS4z9s.F8_klk24GgTk2LqCT18Nowo1EvUSW7vUx62oL70o_7E&dib_tag=se&keywords=banjo+bolt+tapped&qid=1746394800&sprefix=banjo+bolt+tapped%2Caps%2C138&sr=8-8

This will give you an idea of what the modification to the bolt is or you can purchase bolts like this, but make certain what size bolt you have on your machine. They can come in 10mm, 12mm, 14mm, or 16mm.

Personally I have just drilled out the center on my bolts and tapped them with 1/8npt to install a fitting to connect my gauges to.

 

[Matoyan]

I went and was checking the tractor over and making sure all of the fittings and such and decided to lift tear end and see what happens. The wheels definitely turn in all 3 speeds both forward and reverse but I did notice that it’s very easy to stop the turning with your hand. The other side still spins though.

May 5, 2025

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May 5, 2025

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[ruger1980]

That is the function of a differential. It allows the drive wheel speeds to differentiate from each other. You can stop one wheel and the other will spin at twice the speed as both would normally.

 

[Matoyan]

Can I unscrew the check and high pressure relief valves and the charge relief valve to inspect them?

 

[PoTreeBoy]

View attachment 154030
Can I unscrew the check and high pressure relief valves and the charge relief valve to inspect them?

If you can't test the relief pressure, take it to the dealer and have them do it. The relief valve doesn't come out that way. That view is of the end of the relief valve.

 

[ruger1980]

The charge relief is only able to be removed from inside the case. The charge check/high pressure relief can be removed but unless you see something visually wrong there is no way to determine of the are faulty. If the issue is with a check or high pressure relief it is generally in one direction and not both. And if there were an issue with a neutral valve it would also likely be one direction not both.

 

[Matoyan]

The charge relief is only able to be removed from inside the case. The charge check/high pressure relief can be removed but unless you see something visually wrong there is no way to determine of the are faulty. If the issue is with a check or high pressure relief it is generally in one direction and not both. And if there were an issue with a neutral valve it would also likely be one direction not both.

So you made me think. I went and tested the tractor again and reverse always works better than forward. It still won’t climb a “hill”, but reverse seems to work better than forwards.
I’ve ordered the new bolts so that I can check pressure.