Oil & Fuel BX2200 HYDRO FILTER BLOWING. HELP!!

[mike1moss]

I have a 2001 kubota bx2200. The forward/reverse pedal began to get stuck after a couple of hours of operation. The next morning when I started it to use it, hydraulic fluid was pouring out at the filter gasket. Inside the filter was collapsed. I thought bad filter so I replaced the filter added fluid and drove it for ten minutes. The next morning started the machine and fluid was pouring out again. The new filter appeared to have over pressurized. The filter gasket end had expanded from its position by about 3/8" as if it was getting an extreme amount of pressure. Any ideas of what the issue may be?

 

[leonz]

My first thought is the relief valve being bad and stuck nearly shut from debris,
but may be it is old enough now that it may need a new directional valve.

Is this filter equipped with a spring bypass valve internally to allow it to safely release the system pressure?


How often do you grease the direction control pedal? if the range of motion is restricted it will create back pressure and lots of problems including air bubbles.

 

[mike1moss]

We do not grease the pedal often and it was getting stuck. I tore the whole machine down and did not see anything obstructing the relief valves. Which would cause excessive pressure, being stuck open or stuck shut? Where do I find the directional valve?

I do not think the filter has any pressure relief. Does the entire system have any way to vent or release pressure?

Thanks

 

[bp fick]

We do not grease the pedal often and it was getting stuck. I tore the whole machine down and did not see anything obstructing the relief valves. Which would cause excessive pressure, being stuck open or stuck shut? Where do I find the directional valve?

I do not think the filter has any pressure relief. Does the entire system have any way to vent or release pressure?

Thanks

The dip stick "vents". I believe. Might want to check that for cleanliness, but hard to believe that much pressure built up just because of that!!!

 

[leonz]

We do not grease the pedal often and it was getting stuck. I tore the whole machine down and did not see anything obstructing the relief valves. Which would cause excessive pressure, being stuck open or stuck shut? Where do I find the directional valve?

I do not think the filter has any pressure relief. Does the entire system have any way to vent or release pressure?

Thanks

the forward and reverse valve is the foot pedal.

 

[EE_Bota]

Hi, sorry for your troubles. I have a BX2200, and the service manual as well. When I get home, I will look into it. If you are on the forum before I post back, you may gain some insight from other posts I have made about this transmission. If you are willing, please answer the following questions:

1)Are you using the proper Kubota brand filter for the tractor?
2)What fluid are you using?
3)When is the last time you changed the fluid?
4)You say the filter collapsed. How do you know, or rather, what do you mean by the term collapsed? Am I correct in assuming that the shell was fine, but when you look down into the filter through the threaded mounting hole, the media has collapsed into that area?
5)On the second failure, you said something that made it sound like the filter shell deformed. Did it deform in such a way that the filter shell was pushed away from the mounting boss in the axial direction, leaving no compression of the filter gasket?
6)You said something that made it sound like you tore the transmission down. What did you take apart?

Sorry to ask so many questions. I will mention some theories when I get home, and have the hydraulic schematic to which I can refer.

 

[bp fick]

EE_Bota

Those are the right questions.

 

[EE_Bota]

EE_Bota

Those are the right questions.

Thanks, that takes a bit of the worry out of asking so many. I didn't want to sound like I was trying to hassle the OP.

I may as well mention my guesses, or how I would proceed, were I the OP.

On the BX2200, that filter cleans the oil just before the hydrostatic drive. The flow rate at that point is priority flow, therefore 1.8 gallons/minute. The maximum pressure at the filter in the event of a system fault would be full system pressure. The amount of pressure that should normally be there is 42-71psi, and is controlled to that pressure range by the charge relief valve.

The system faults that would make the pressures go from the normal 42-71 psi range to some higher range are, as I see it, in order of likelihood:

a)Presuming correct filter, and correctly installed: complete filter blockage due to system contamination. This could collapse the media, and if the media does not also break open (effectively ending the blockage), then the filter shell must yield. The most common way I have seen the shell yield is similar to if you put a pulley puller on it, and tried to pull is straight off the mounting nipple. This releases compression of the gasket, and the event is ended when all the fluid is gone. Note: This should not happen if the filter has a bypass, but the hydraulic diagram for this unit shows no symbol that would indicate a bypass.

b)Transmission vent blockage. The transmission oil level is quite high in these units, and the temperatures get way higher than industrial hydraulics, so the pressures could get quite high. It seems unlikely to me that the filter would go before the axle seal, but I suppose it could happen. Unless the OP is missing the fact that the oil was leaking at shutdown, which seems unlikely, then the fact he sees the problem at start-up would be more indicative of a) rather than b). Also, a deformed filter shell could result, but there is absolutely no reason a clogged vent should collapse the filter media.

c)Charge relief valve problem. Most of the spin-on filters I have been involved with for hydraulic service have a limit of ~100 psi. Some reliefs may relieve at slightly higher pressures at start-up due to increased oil viscosity, but slightly is the key here.

I wish you the best of luck on the problem, and please let us know what you do find. Some of us still rely on the BX2200, and many of the latest models are very similar, so many of us want to know the answer to this one.

 

[Volfandt]

I have a 2001 kubota bx2200. The forward/reverse pedal began to get stuck after a couple of hours of operation. The next morning when I started it to use it, hydraulic fluid was pouring out at the filter gasket. Inside the filter was collapsed. I thought bad filter so I replaced the filter added fluid and drove it for ten minutes. The next morning started the machine and fluid was pouring out again. The new filter appeared to have over pressurized. The filter gasket end had expanded from its position by about 3/8" as if it was getting an extreme amount of pressure. Any ideas of what the issue may be?

While not common, it has been posted and your trouble sounds very similar.
Theres more info in this link: http://www.tractorbynet.com/forums/kubota-owning-operating/129499-bx2200-serious-problem.html

EE_Bota, your reasoning seems sound and on track.
Good luck
Dave

 

[mike1moss]

Broke down and took the machine to the dealer in Oxnard, CA. I tore down the entire machine and checked the relief valves for blockage, found nothing. Not knowing enough about these machines I did not want to tear down the HST pump. The dealer found melted plastic pieces in the unit and said that it grooved the plates inside the HST pump. I am not familiar with the internals so I not sure what they are referring to.

The machine is back together and seems to be working first day back. After $2700.00 repair. The new HST pump was $1500.00. This seems like a weak point on the machine considering it was damaged so easily and costs so much to replace.

Hope this helps someone out there. It seems as the dealer just replace the entire HST unit. Rather than re-build we'll see how long it lasts.