It has been a real good tractor for 18 years with little gone wrong but a week ago the hydrolic filter fell off and had the threads of the nipple still in it. I took the filter holder to a shop and had it shaved down so the nipple will reach the filter now, new fluid, new filter and it worked for 5 min then the filter 0 ring blew out and sprayed me with oil. I reset the 0 ring and limped back to the shop and got out my service book and started looking for reasons for high pressure in the filter. It seems there is a charge relief pressure valve somewhere but it does not tell me where. I need help with this one and other ideas too if you have them. tom
b2150hst
- Thread starter Oldoldoldman
- Start date
Located on the right side of the transmission. It will have 3 pipes into it if you have manual steering, 5 pipes if you have power steering. The Pressure relief section is the nut near the bottom pointed to the rear of the tractor. CAREFUL! there's a few springs, shims (to change pressure) and poppets in that block.
Go to the parts book...http://www.kubota.com/part/partsList.aspx
accept conditions, enter model number, expand [+]hydraulics, view "hydraulic block," to see the bits and pieces.
Go to the parts book...http://www.kubota.com/part/partsList.aspx
accept conditions, enter model number, expand [+]hydraulics, view "hydraulic block," to see the bits and pieces.
Thank you for your reply. I think the pressure relief you are indicating is for the hydraulics lift strength and the one I need to find is the charge pump pressure relief. It is my understanding the return from the loader goes into the charge pump line and when I lower the loader its discharge goes into the charge line and if the relief isnt working right the charge pressure which goes through the hydraulic filter will blow the filter or its 0 ring. I need to know where the charge relief is so I can check it. Do you think the one you were talking about is the right one for that? tom
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Do you have an add-on hydraulic pump for the loader?
If you do then it is specific to the brand you added. Some have them in the pump, some have a pressure regulator near the spool valves.
If you do then it is specific to the brand you added. Some have them in the pump, some have a pressure regulator near the spool valves.
I do not have an add-on pump, I have the stock Kubota loader on it put on in 1994. I think it is a 350 model. The tractor has ps too. The pressure relief Im looking for has nothing to do with the loader though. Its my understanding there is a pump that keeps the hydrostatic drive system pressurized and is called the charge pump. It dosent run anything but keeps constant pressure from the transmission sump to other pumps. The charge pump has a pressure relief to keep constant low pressure through the hydraulic filter and then on to the hydrostatic drive. When I raise or lower the loader the return fluid dosent dump into the transmission sump on this model, it goes into the charge line and it seems the charge pump line going to the hydrostatic drive is over pressuring because the charge relief is stuck and it causes the hydraulic filter to blow its seal when I lower the loader. What Im looking for is the charge pump line relief valve. It has nothing to do with hydraulic pressure to or from the loader and I think is located somewhere on the transmission housing. Note, I could be wrong on the location of the charge relief valve but since it goes through the filter to the hydrostatic drive and is low pressure I would think it would be near that and not on the high pressure block for the loader. tom
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Kubotas not withstanding as this would apply to most hydralic systems that use the spin on, thin wall metal hydralic filters.... they are either installed on the suction side of the pump or installed on the return line on most non aircraft hydralic systems.
Normal non aircraft hydralic filters normaly are NOT designed to see more that a maximum of 200 psi (burst) or about 1/3 to 1/2 half that working. Hence, they are NOT normally in the pressure supply line, therefore they would never see the working pressure of 1500 to 3000 psi.
If you are blowing a filter off, then look for a restiction in the return line, OR the filter mount is screwed up / wrong filter is installed / etc.
David
Normal non aircraft hydralic filters normaly are NOT designed to see more that a maximum of 200 psi (burst) or about 1/3 to 1/2 half that working. Hence, they are NOT normally in the pressure supply line, therefore they would never see the working pressure of 1500 to 3000 psi.
If you are blowing a filter off, then look for a restiction in the return line, OR the filter mount is screwed up / wrong filter is installed / etc.
David
Try the rear of the 3 point control valve, near the top. That relief seems to be in-line with the return from the charge pipe.