Help with BX25D Hydraulic issue

[LividTaco]

Got a 2015 BX25D that started sucking air intermittently couple months ago. Strange to me it's not all the time (at least that I've noticed) and that it doesn't always, until recently, cause power loss in backhoe or FEL.

-FEL quick connects appear fine
-Backhoe quick connects appear fine though sounds like possible air movement in return/recirculating line so got male/female on order just in case.
-No visible leaks on all hydraulic lines
-Trans/hydraulic oil changed 2 weeks ago and again this past weekend due to oil becoming black within a week
-PTO Control dial was very hard to operate due to shafts being bent, upon removal found oring cut in 2. (Think I cut it in 2 on accident removing it but good possibility it wasn't seated correctly causing removal to cut it between threads
-Disassembled tractor all the way down to pump, no oil spots or anything from small leak
-Noticed foaming in oil month or so ago, but as stated it seems intermittent.
-transmition casing gasket peeling off from outside in many places. (Hard to tell if actual seal inside/out is/has been broken. Going to apply additional layer around casing just in case)
-Removed both FEL and backhoe attachments amd then ran tractor and hydraulic fluid still foaming. So definitely tractor side (I would assume)

Has anyone ekse had this or similar issue? If so what was fix? If not any suggestions or anything else i should check. Believe the PTO CONTROL dial o-ring to be the culprit which would explain the intermittent, as I don't use any mid attachments and I had recently used dial to get under armor on/off for filter replacement.

Also by chance anyone have pictures of hydraulic line flow/functions��?

Thanks!

 

[oldnslo]

Sucking air is typically on the pump inlet side of things. Can also be on a return side if high fluid velocity is present. I don't recall if the BX models had hose for the pump inlet or not. If yes check to make sure all of the connections, hose clamps, etc. are tight. Vacuum will allow air in but does not always allow oil to drip back out when the machine is shut off.

 

[radioman]

-FEL quick connects appear fine

they may appear to be fine , but sometimes its not seated in all the way. I'd relieve the pressure using joystick with tractor off, disconnect and reconnect. check the o rings.. all it does is give better seal against oil drips
-Backhoe quick connects appear fine though sounds like possible air movement in return/recirculating line so got male/female on order just in case.
the short hose is designed to feel noisy while running. i think you are over reacting here.
-No visible leaks on all hydraulic lines
good.
-Trans/hydraulic oil changed 2 weeks ago and again this past weekend due to oil becoming black within a week
how is this possible? mine is still dark tanish after 4 years. did you replace the filter too?
-PTO Control dial was very hard to operate due to shafts being bent, upon removal found oring cut in 2. (Think I cut it in 2 on accident removing it but good possibility it wasn't seated correctly causing removal to cut it between threads
Are you referrin to the flow control? I usually set it and forget it.
-Disassembled tractor all the way down to pump, no oil spots or anything from small leak
ok -- thats good news. nothing to worry about
-Noticed foaming in oil month or so ago, but as stated it seems intermittent.
mine foams after hard use if i check right away, but if i check it cold -- is prettty flat oil
-transmition casing gasket peeling off from outside in many places. (Hard to tell if actual seal inside/out is/has been broken. Going to apply additional layer around casing just in case)
the extra gasket is probbly oversized, if there is no leaks, i would NOT cover it it up. if it started leaking at the gasket - how will you know if it was covered up?
-Removed both FEL and backhoe attachments amd then ran tractor and hydraulic fluid still foaming. So definitely tractor side (I would assume)
again -- normal after use.
Has anyone ekse had this or similar issue? If so what was fix? If not any suggestions or anything else i should check. Believe the PTO CONTROL dial o-ring to be the culprit which would explain the intermittent, as I don't use any mid attachments and I had recently used dial to get under armor on/off for filter replacement.
???? if you are referring to the flow control on right side near floor -- why do you need to fiddle with this? if you bought a metal sheild and the shaft is in way - then something is not lined up right or there is too much metal on that plate.

Also by chance anyone have pictures of hydraulic line flow/functions��?

i dont think i have a copy -- i just need to get the work shop manual myself.

Thanks![/QUOTE]

[SUB][/SUB]

 

[Tractor Seabee]

In reviewing the WSM circuit diagram I see no place where the circuit is under a vacuum (required to suck in air). The return lines to the tank are sized to have a nominal pressure and dump to the atmospheric pressure Tank. Only possibility is the suction strainer gasket. That seems unlikely if the tank is full. If the strainer is plugged w/gunk then the fluid could vortex at the suction and suck in air. Otherwise I am baffled. 1500 hours on my BX and no hydraulic problems except a bunch of black gunk and metal filings in the strainer at the 50 Hr service. None since.

Ron

 

[LividTaco]

Filters been changed twice now, and yes I believe it is the flow control valve and I normally wouldn't fiddle with it but if you have BXPANDED under armor on the tractor it requires you to lower your mid mounts and then raise again to secure it in place... have to drop it to change trans fluid filter.. Issue is it drops sooooooooo slow, no matter what I do, which way I turned it it did not effect drop speed. As stated it was bent and basically unusable.

Far as Strainers go I've cleaned it twice. I found another one on back side of pump itself which I cleaned too.
After pulling the dial assembly out I did notice rust right up front where the fluid sits, which is strange to me seeing as how it stays lubed... also when i just took my channel locks and unscrewed it firmly (carefully but at this point didnt care if it broke or not just prayed for no chewed up threads) it popped off and began to pour out hyd fluid. I cleaned it up real good, put a new oring, reset stopper and straightened the shafts, inserted and then popped retainer clip on and it actually tightens and stops firm and loosens stops firm, after letting it sit in open and closed positions it seems as if no leaks, so yay on that working.

And when I say foaming fluid with FEL/BH removed I mean foaming to point of overflowing just cruising around at 2500-3k rpm... not to mention hydraulic lines being so hot you can't touch them immediately. Plus mine is foaming with like 1/10th the back hoe power. 2-3: in ground and it bogged down

And by vortex what do you mean. Did notice sometimes before foam gets so thick it overflows the the hydraulic fluid in the pump tank was spiraling rather rapidly, is this what your referring to? And I checked that little rubber drip hose for leaks and it was good. Honestly I think it was that **** control valve and that retainer clip not being set right causing that valve to be partially open at all times. It does attach directly to the pump.

Oh one other thing. On the strainer on the back side ofor the pump there's a valve above or below it, cant remember but does a push pull motion... those holes on that valve suppose to be wide open or?

 

[LividTaco]

Filters been changed twice now, and yes I believe it is the flow control valve and I normally wouldn't fiddle with it but if you have BXPANDED under armor on the tractor it requires you to lower your mid mounts and then raise again to secure it in place... have to drop it to change trans fluid filter.. Issue is it drops sooooooooo slow, no matter what I do, which way I turned it it did not effect drop speed. As stated it was bent and basically unusable.

Far as Strainers go I've cleaned it twice. I found another one on back side of pump itself which I cleaned too.
After pulling the dial assembly out I did notice rust right up front where the fluid sits, which is strange to me seeing as how it stays lubed... also when i just took my channel locks and unscrewed it firmly (carefully but at this point didnt care if it broke or not just prayed for no chewed up threads) it popped off and began to pour out hyd fluid. I cleaned it up real good, put a new oring, reset stopper and straightened the shafts, inserted and then popped retainer clip on and it actually tightens and stops firm and loosens stops firm, after letting it sit in open and closed positions it seems as if no leaks, so yay on that working.

And when I say foaming fluid with FEL/BH removed I mean foaming to point of overflowing just cruising around at 2500-3k rpm... not to mention hydraulic lines being so hot you can't touch them immediately. Plus mine is foaming with like 1/10th the back hoe power. 2-3: in ground and it bogged down

And by vortex what do you mean. Did notice sometimes before foam gets so thick it overflows the the hydraulic fluid in the pump tank was spiraling rather rapidly, is this what your referring to? And I checked that little rubber drip hose for leaks and it was good. Honestly I think it was that **** control valve and that retainer clip not being set right causing that valve to be partially open at all times. It does attach directly to the pump.

Oh one other thing. On the strainer on the back side ofor the pump there's a valve above or below it, cant remember but does a push pull motion... those holes on that valve suppose to be wide open or?

 

[Tractor Seabee]

A vortex is like your bathtub drain when the water swirls in a circle and sucking air down the middle. Indicates the pump is not getting enough fluid. here is no way to get air mixed into the fluid unless there is a negative pressure inside the system. That is also my non-engineer idea based on high school science. I would be equally baffled as you are; just does not add up in my feeble brain.

Ron

 

[LividTaco]

If anything I would say there is a bit too much fluid (just over line) I've even cleaned the little filter in the pump even though it wasn't dirty.. and im still curious what the valve is under the pump filter and how those holes/slots are suppose to be, they were partially closed when I tore it down and since then I've opened them up but it didn't do anything.... I almost got wiring harness factory styled in the body carriage, maybe tomorrow I can start pricing it back together at least enough to turn it over and check out any changes

 

[ch1ch2]

And when I say foaming fluid with FEL/BH removed I mean foaming to point of overflowing just cruising around at 2500-3k rpm... not to mention hydraulic lines being so hot you can't touch them immediately. Plus mine is foaming with like 1/10th the back hoe power. 2-3: in ground and it bogged down

I do not know BX25D's but I think this is the issue. It is not sucking air. It is foaming from being too hot. Is it a HST? Pump not getting enough fluid or maybe an orifice stopped up with debris like teflon tape.

 

[oldnslo]

With the FEL & BH removed did you the hoses looped to allow the pump flow to circulate? Heat and aeration / foaming would indicate blowing oil over a releif valve.

 

[LividTaco]

Yes it is an HST and yes I did make sure that the recirculating hose was on and tight... now something blocking a valve partially... and you mentioning Teflon tape.. there are quite a few connections I've noticed that seem to have been re-teflon'd and had/have string like prices of Teflon peeling off on the outside. Very real possibility I got 1 or 2 peeling inside... working late tonight but no point risking reassembly without at least checking all the hard to get to valves while they are accessible.. thank you for the input ch1ch2. I will update with findings.

Also guess I'll need to go ahead and buy yet another 5 gallon of oil heh.

Opinions on draining oil into clean container and then reusing? And oil is definitely getting super hot.. that why my discoloration so fast?

And which relief valve possibly? That the valve under the pump filter?

 

[oldnslo]

Livid,
I would suggest installing a pressure gauge in the suppline line to your FEL control valve. This way you can monitor what pressure the system is operating at while doing no work. Not sure what it should read but i would think 250 - 300 PSI max while just standing still or driving around without the FEL or BH. This will at least provide some insight on where to start looking for a potential problem. If this pressure stays low then may have to look at the HST or steering circuit, etc.. I believe all of the BX models had a single pump that feeds into a priority flow control. This flow control directs oil first to the steering circuit and excess oil goes to the FEL & BH. The steering circuit had seperate relief from the implement hydraulics. I believe the implement relief was located behind the left rear wheel.

 

[Leejohn]

Roy maybe explain to him how to check it with temp. gun. I don;t want confuse him you got him heading on the right track.

 

[Tractor Seabee]

If anything I would say there is a bit too much fluid (just over line) I've even cleaned the little filter in the pump even though it wasn't dirty.. and im still curious what the valve is under the pump filter and how those holes/slots are suppose to be, they were partially closed when I tore it down and since then I've opened them up but it didn't do anything.... I almost got wiring harness factory styled in the body carriage, maybe tomorrow I can start pricing it back together at least enough to turn it over and check out any changes

"Oh one other thing. On the strainer on the back side ofor the pump there's a valve above or below it, cant remember but does a push pull motion... those holes on that valve suppose to be wide open or?"

Taco, Are these the same valve you are discussing? If so and it is located behind the left rear wheel; it is either the relief valve or the priority flow valve. The relief valve is nothing but a spring and a disc. The thickness of the disc determines the pressure to the implements. (They come in various thicknesses and can be stacked. 1 mm = 39 PSI.) The flow valve I have never been into and the WSM is kinda blank on whether adjustable. Those are the only valves integral to the HST and serviceable externally. Checking the PRV requires a pressure gauge and the priority valve a flow meter; it divides the flow from the pump to the power steering and the implements.

The WSM does not list the foaming oil in the trouble shooting chart. As one other poster stated heat is probably your problem after exploring all the other ideas. If the relief valve is messed up that will heat up the fluid pretty fast trying to put the whole flow through a small hole.

You have already done more that I would w/o the WSM. Are you still in warranty? If so; it may be time for the dealer shop.

LOL, Ron

 

[LividTaco]

I believe the priority valve and flow control are right there by left rear wheel and I guess I would be talking about the flow control. It's smaller on one end then the other like a cone with top cut off. It's got 2 sets of like 4-5 holes on each half. There's a plunger like deal in the center that appears to close the top off completely and open the bottom and vise versas when released. There looked to be a cylindrical peice in the middle so to see if it would move I pushed it a bit with a control screw driver. Originally the 4 or so holes staggered down from wide open to almost closed. When pushing the peice in the middle all the holes lined up and it was wide. I think I might have fixed the issue but ran out of time tonight.. gonna take my 3 hour nap before work and tomorrow evening I try some mors