BX24 blowing hydraulic filters

[5030]

Motion Industries also has the Glycerine filled gage and the adapters. Matter of fact, that is where mine came from. Needed a special adapter to check the hydraulic pressure on my old, traded in NH round bailer. Still in my toolbox, not needed because my new Kubota BV Sileage Special is fitted with a gage from the factory.

 

[oldnslo]

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.

 

[dodge man]

I looked up where the suction screen is and it’s sort of behind the wheel on the left side, I don’t think you mistake a leak there for the filter leaking.

 

[Suki]

I’m pretty sure they do have a suction screen, which can get pretty clogged. I don’t know if that coukd cause the filter to keep blowing off.

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.

So we changed pressure relief value and started with no shims....got it to 1500 psi and it blew the filter. It absolutely destroyed the inside of last filter. We will check screen and change coupler that was unplugged from backhoe and connected back into system. Not sure what you mean by charge pump loop? We will also check priority flow control. We did this same hookup last summer with no issues. We will change coupler today. Five Kubota filters later........

 

[Suki]

Motion Industries also has the Glycerine filled gage and the adapters. Matter of fact, that is where mine came from. Needed a special adapter to check the hydraulic pressure on my old, traded in NH round bailer. Still in my toolbox, not needed because my new Kubota BV Sileage Special is fitted with a gage from the factory.

We bought one from bxexpanded.com....great company and hooks directly.

 

[Suki]

I looked up where the suction screen is and it’s sort of behind the wheel on the left side, I don’t think you mistake a leak there for the filter leaking.

It is right above the pressure relief 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.

Can you tell me how to check charge pressure?

 

[rScotty]

Can you tell me how to check charge pressure?

So we changed pressure relief value and started with no shims....got it to 1500 psi and it blew the filter. It absolutely destroyed the inside of last filter. We will check screen and change coupler that was unplugged from backhoe and connected back into system. Not sure what you mean by charge pump loop? We will also check priority flow control. We did this same hookup last summer with no issues. We will change coupler today. Five Kubota filters later........

 

[rScotty]

"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.

rScotty

 

[oldnslo]

Per schematic attached by rscotty the filter is after the PTO relief and before the HST charge relief. If this is correct the charge relief would be the only relief that would affect the filter or an obstruction between the filter and charge relief.

Other potential concern would be if the priority flow valve is somehow allowing more flow to steering- charge circuit which may increase charge pressure. I recall some posts in the past about priority valves failing but do not recall what the failure mode was.

Suki,
I do not recall - remember how to check the charge pressure but 99% positive that it explains how in the work shop manual

 

[rScotty]

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

 

[rScotty]

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

If you figure out how to get the WSM, setting the HST reliefs & charge pressure is on pg. 257.
The PTO works on 150 psi, but the HST reliefs at 3000 psi. That is enough pressure to be deadly and cut a foot off.
Please be careful. 10 seconds max on the relief. The WSM implies that those HST relief valve had a nut that coud back off, .

 

[Suki]

Scotty, thank you so much for your info. The last filter was blown apart inside. We ordered them a Kubota dealer and they were the hydraulic ones.

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

thank you so much. We did the Pressure test with gauge on loader and pressure was at 1250 or just a bit higher and it blew the filter. Does this mean it is happening between filter and loader? Line flattened, kinked?

 

[Suki]

Scotty, thank you so much for your info. The last filter was blown apart inside. We ordered them a Kubota dealer and they were the hydraulic ones.

thank you so much. We did the Pressure test with gauge on loader and pressure was at 1250 or just a bit higher and it blew the filter. Does this mean it is happening between filter and loader? Line flattened, kinked?

It blew the filter inside all apart.

 

[Suki]

Per schematic attached by rscotty the filter is after the PTO relief and before the HST charge relief. If this is correct the charge relief would be the only relief that would affect the filter or an obstruction between the filter and charge relief.

Other potential concern would be if the priority flow valve is somehow allowing more flow to steering- charge circuit which may increase charge pressure. I recall some posts in the past about priority valves failing but do not recall what the failure mode was.

Suki,
I do not recall - remember how to check the charge pressure but 99% positive that it explains how in the work shop manual

Thank you for the info. Gonna print it out. So frustrating. We tested pressure according to manual and the loader didn't get to 1300psi and the filter blew...it destroyed the inside of the filter.

 

[Suki]

Scotty, thank you so much for your info. The last filter was blown apart inside. We ordered them a Kubota dealer and they were the hydraulic ones.

thank you so much. We did the Pressure test with gauge on loader and pressure was at 1250 or just a bit higher and it blew the filter. Does this mean it is happening between filter and loader? Line flattened, kinked?

Do you think this translates to a BX24D?

 

[oldnslo]

Thank you for the info. Gonna print it out. So frustrating. We tested pressure according to manual and the loader didn't get to 1300psi and the filter blew...it destroyed the inside of the filter.

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.

 

[dodge man]

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.

 

[rScotty]

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.

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.

 

[KWentling]

Pretty late to the party here, but looking at the WSM for my BX22, the filter is in the HST Loop. I would expect the problem to be stuck check valves in the high pressure relief valves forward/reverse. Nothing to do with loader relief valve. They are located, looking up from the bottom of the tractor, between the filter and the front PTO shaft.