BX24 blowing hydraulic filters

[TMGT]

The OP didn't say what the loader was doing when pressure was measured. That pressure should vary from (0) psi to full relief pressure (2900 psi) depending on what they are trying to lift . 1250 psi is about right for just raising and lowering an empty FEL.

There are a number of other ports where a pressure gauge can be hooked up. Basically anywhere that there is a relief valve, a pressure gauge can be hooked up. That is why the Amazon gauge kits come with so many adapters, gauges, & hoses. There are lots of relief valves identified in the WSM. One of them is not doing its job. It should pretty obvious because it should be hot and rattling and squealing.

We never did ask what hydraulic oil was used to replace the old when you replaced the first filter? Can you find a can and copy the label? Old hydraulic oil is sort of milky and stringy if it has gotten water in it.

Factory relief on the loader circuit is about 1750psi, empty loader lift is maybe a couple hundred psi.

The filter on the BX is part of the hst circuit, he'll have to find the test ports on the hst to check those pressures. I haven't had to do pressure test on a BX but I imagine it similar to the B7200 I had to test a while back, should be some plugged ports on the hst assembly itself to check the different circuit pressure.

I would like to see what the filter looks like, only seen interior of filters collapse on suction due to restriction or blow out the can from overpressure (or blow the threads off the mount!).

 

[WranglerX]

What bothers me is everybody is saying filter is in hydraulic circuit which I interpret as high pressure side.... Confused as to whether filter could stand 1700-1800 PSI... Would seem to me filter would be on low pressure return to tank side, or suction side....

 

[dicktill]

What bothers me is everybody is saying filter is in hydraulic circuit which I interpret as high pressure side.... Confused as to whether filter could stand 1700-1800 PSI... Would seem to me filter would be on low pressure return to tank side, or suction side....

I think that the hydraulic filter is on the return flow from the steering valve, just as it is on the Massey Ferguson GC's. That's what the diagram that @rScotty posted above (post #31) shows. On the Massey Ferguson GC's that pressure is controlled by the power take off (PTO) relief valve set at ~79 psi. If that pressure relief valve were jammed open than the pressure could be much higher and could be causing the filter to blow.

Sorry, on edit, that doesn't make a whole lot of sense. The relief valve is normally open most of the time as the flow has nowhere else to go unless the PTO valve is open, and then that flow isn't much. Jamming it shut would increase the pressure, but the filter shouldn't see that. So, seems like it needs something downstream of the filter to cause such a high pressure. IDK (I don't know) ....

 

[altoonapillarrock]

I am 83 and I have learned so much about my 2008 BX24 from tractor by net and the occasional YouTube video. Thanks so much to all you folks who contribute.

 

[oldnslo]

What bothers me is everybody is saying filter is in hydraulic circuit which I interpret as high pressure side.... Confused as to whether filter could stand 1700-1800 PSI... Would seem to me filter would be on low pressure return to tank side, or suction side....

On the BX the factory filter is in the charge pump circuit for the HST. So low pressure circuit

Standard spin-on filters are typically rated for around 100 - 150 PSI with normal operation at 50 PSI or less.

I do not recall if it has been confirmed that this is the filter in question but suspect that it is.

 

[TMGT]

On the BX the factory filter is in the charge pump circuit for the HST. So low pressure circuit

Standard spin-on filters are typically rated for around 100 - 150 PSI with normal operation at 50 PSI or less.

I do not recall if it has been confirmed that this is the filter in question but suspect that it is.

It is, the only cartridge filter is the hst filters, the only other hyd filter is the suction screen. I couldn't remember the exact pressure of the charge circuit but most are only 1-200psi.

I would really like to see what the failed filters look like.

 

[TMGT]

To the OP, does the filter fail immediately or only after an operation, like driving or turning or using the PTO?

 

[rScotty]

Sad to say, but most older tractor hydrulic problems are due to contanimated fluid that forms globs that won't pass through the various ports. Then those blobs cause an intermediate failure which puts more crud into the system. There never was anything wrong with it except age & old fluid

My guess with this one is there are blobs on top of blobs of old hydraulic fluid and water all the way through blocking flow....especially where the output of the hydraulic filter enters the HST. That appears to be a complete blockage. You may have to probe that to get the goo out. Or disassemble.

The first thing to do with any older hydraulic system that begins to show problems is to drain it, flush it, clean off any cleanable filters - and run the flush through many times with an open hydraulic filter. this can take hours. Then when/if the third or forth flushing fluid begins to look like clear oil again, put in real transhydraulic fluid and a filter.

This should have been done when the first filter failed....all my opinion, but does anyone have a better?

rScotty

 

[Suki]

doesn't adding shims increase the pressure?

Went with no shims.

 

[Suki]

Sad to say, but most older tractor hydrulic problems are due to contanimated fluid that forms globs that won't pass through the various ports. Then those blobs cause an intermediate failure which puts more crud into the system. There never was anything wrong with it except age & old fluid

My guess with this one is there are blobs on top of blobs of old hydraulic fluid and water all the way through blocking flow....especially where the output of the hydraulic filter enters the HST. That appears to be a complete blockage. You may have to probe that to get the goo out. Or disassemble.

The first thing to do with any older hydraulic system that begins to show problems is to drain it, flush it, clean off any cleanable filters - and run the flush through many times with an open hydraulic filter. this can take hours. Then when/if the third or forth flushing fluid begins to look like clear oil again, put in real transhydraulic fluid and a filter.

This should have been done when the first filter failed....all my opinion, but does anyone have a better?

rScotty

So the hydraulic fluid but will certainly let the guys know. Our friend, a. hydraulics guy has been doing some research and after all the testing, thinks a valve may be stuck. Also, not sure why the pressure test happens where it does and not in the line itself. Will keep everyone posted.
We are also checking to make sure correct filters were sent from Kubota.

 

[Suki]

Is there still on old gasket on the mounting surface by any chance? Were the filters tightened to spec?

No old gasket.

 

[Suki]

Cheap aftermarket filters or genuine Kubota fikters? You realize there is internal pressure on the hydraulic filter?

Kubota stuff only, but Kubota is checking to see if right filter as this is a 2006.

 

[Suki]

Did it happen once you started using the 3pt?
Or using the deck lift?

Have used all before. Mowed and worked the bucket for 10 plus hours before it happened, and then it happened again.

 

[Suki]

That's about what I am thinking. 5030. Tractors have a lot of built-in safeguards against too much hydraulic pressure. Hard to imagine everything failing and high pressure resulting.

Yes, the "adding shims to the relief valve" thing scares me too. I can't think how adding shims to a relief valve is going to lower the pressure. Usually it raises pressure.

A gauge test set is a good idea, everyone should have one. 5000 psi and liquid filled - Amazon has complete guage, hose, and adapters in a kit for less than $100.....sounds like the OP spent that much on hydraulic filters.

Suki, are you sure that the engine oil and the hydraulic filter didn't get exchanged? The hydraulic filter costs twice as much, it's heavier, and the shell is thicker. But they are about the same size and mounting.

I believe that model does have a cleanable screen under the hydraulic filter. But if it is clgged or missing it usually causes the opposite problem - too little pressure rather than too much. However, if it is missing or installed wrong it can cause a leak that might make you think the hydraulic filter "blew". You might want to describe how it blew. BigNoise? Or just lots of oil??

By far the most common hydraulic overpressures are caused by hoses. Either the quick connect ends are not seating well or the hoses are connected to the wrong ports. While waiting, I'd take them all off - one at a time - inspect them and make sure the connections are correct. Push on the quick change valves with something to make sure they are seating. And check for a mysterious oil leak or split down by the cooling fan underneath. That's a known trouble spot.
Luck,
rScotty

 

[Suki]

Thank you for the info. Our friend is finally looking at it. The Kubota dealer is three weeks out. He is a hydraulics guy and his research has sent him to a stuck valve possibly. No shims were added and a pressure test at bucket was 1250 when it blew. He says checking pressure at that point on tractor isn't telling you what you need to know. It has to be on the low side before it goes into filter. We have a gauge from bxpanded.com. The mechanics at the dealership have been excelllent but can't get it in for 3 weeks. We received hydraulic filters but they are checking to see if they sent the right ones. Also the filter that blew first was a year old. We don't run it in the winter, but it ran all last summer and fall and this spring. Will keep you posted. Something is forcing the pressure up on the low side of filter....may be a stuck valve.

 

[Suki]

Isn’t the filters on the BX in the charge pump loop not return loop? Does the BX24 have priority flow control for steering that then feeds PTO and charge circuit. Should be a relief for steering, PTO and charge in that circuit. If this is the filter in question you need to check charge pressure.

Excess flow goes to implement with another relief in that circuit.

Been several years since sold my BX so don’t remember for sure.

Excessive flow is going to hydraulic filter.

 

[Suki]

"Charge pressure" is just another way of defining a specific pressure at a point in a hydraulic system. More specifically, In tractors with HST, "charge pressure" has come to mean the operating pressure within the HST. Some HST tractors have a separate hydrostatic pump and special filter for the HST. The BX24 doesn't have that extra filter.

The Kubota Workshop manual will define a port on the HST to hook your pressure gauge. That is the "charge pressure" you want

You keep saying "blew the filter" .... I am still wondering what that means? Did it split open?

Here is a hydraulic diagram and WSM for the BX23S. My guess is your BX24 is very similar.
It wouldn't surprise me that the problem with the overpressure to the filter is due to a problem with the hydraulic PTO valve. That circuit also has its own relief valve that would be worth measuring.

The WSM was too large to attach. PM me & maybe it will come that way. View attachment 3613779

rScotty

It opens at the gasket and it destroys the inside.

 

[Suki]

Suki, I have just tried to send you the BX23S WSM via Personnal Message (PM). Let me know. It has full info. Much better than more recent manuals.
Also found in the WSM more hydraulic diagrams. One identifies (#3) as a relief valve that may also affect your filter pressures. Worth checking, but read the WSM if it arrives.
Nice to see someone willing to do their own diagnostic work these days instead of dealer.
rScotty

View attachment 3613831View attachment 3613832

Do you think they would be the same for a 2006?

 

[Suki]

Could you post a picture or pictures of where this filter mounts Just so that we are all on the same page.

Is this filter in the backhoe loop vs what manual shows as charge pump filter. Curious if backhoe had a filter or is this something added on by an unknown person.

Blowing innards on an element seems very unusual so makes a person wonder what are we missing.

the backhoe wasn't on the tractor. It had been disconnected two weeks before 10 hours of running time. It is after the reservoir I believe, not know terms, but they said on the low side. Our hydraulics friend said checking the pressure after the filter made now sense. Needs to be checked before.????

 

[Suki]

Do you know what the spec is for pressure at the loader? That sounds low but it could be that’s spec for your tractor.

spec is 1800-1850. It is happening before the filter. Replaced complete relief valve with no shims. Once fixed, we will add back. Our hydraulic friend has done some research and we will start with finding if a valve is stuck.