bX23 - Transmission needing replacement
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Harry c
Gold Member
The BH and FEL work from a different pump than the Trans. Bad trans would not affect them.
No info on trans failures.
No info on trans failures.
Volfandt
Veteran Member
There was a post a month or so ago where a poster had to have his rebuilt. Seems it developed a leak (don't recall but I think it was due to a damaged HST filter) and he ran it almost dry, damaging the internals. His problem was a loss of traveling speed and loud metal on metal sounds fromt he HST. Sorry don't recall his moniker. Try a search on BX HST
Like Harry c said, theres a separate hydraulic pump mounted on the HST that supplies pressure for the implement lift/controls and power steering.
Rebuilding and/or replaceing an HST tain't cheap whereas the pump would be considerably cheaper. Haven't read of a pump going out yet but like anything mechanical, it can fail. You may need to get it to a dealer and let him test the pressure. Without a good pressure test we're all just guessing.....
Good luck
Like Harry c said, theres a separate hydraulic pump mounted on the HST that supplies pressure for the implement lift/controls and power steering.
Rebuilding and/or replaceing an HST tain't cheap whereas the pump would be considerably cheaper. Haven't read of a pump going out yet but like anything mechanical, it can fail. You may need to get it to a dealer and let him test the pressure. Without a good pressure test we're all just guessing.....
Good luck
rdsaustintx
Veteran Member
Harry c said:
Nope. BX-23 is a single-pump machine.
Harry c
Gold Member
rdsaustintx said:
Don't mean to contradict but I believe there are 2 pumps. Part no for the hydraulic pump is 6C040-36308. It is a gear type pump and is mounted to the outside of the HST housing. The HST is a variable displacement pump. It is inside the housing. That's the 6 plungers in the diagram.
My BX23 had a transmission failure at 225 hours. I ended up trading it in for a B3030 because it was taking several weeks to get the gears needed to repair it and I wanted a bigger tractor anyway. All the service technician could tell me was that it had a "catestrophic" gear failure. My symtoms were that it would just stop going in reverse or forward. Sometimes the engine would sound like it was under a load but not go anywhere. As I finally got it back on the trailer I could hear mechanical clinking and grinding. The week before I thought it was acting strange and took it to the dealer and they could not get it to act up. The next week it totally bit the dust.
rdsaustintx
Veteran Member
Harry c said:
Huh? Read note 2 if you can't figure out the schematic.
BX23 is a single pump machine.
RDnT
keerym
Bronze Member
rdsaustintx, I would be careful who you accuse of not being able to read the schematic. In the attached schematic, number 10 is the hydraulic pump. Number 11 points to the self contained hydrostatic transmission. With in the transmission is a pump and a motor.
All of those circles and lines mean something. A circle with arrows pointed out means its a pump. One arrow means single direction flow, two arrows means bidirectional. Arrows pointed in means its a motor. A line drawn through the circle means its a variable displacement pump or motor.
In this case, number 10 is the single pump for the hydraulic system. It is single direction flow, fixed displacement. Inside of the hydrostatic transmission is a bidirectional, variable displacement pump and a bidirectional fixed displacement motor.
Also, it would be important to point out that the transmission and the hydraulic system are not separate. According to the schematic, both use a common filter and oil resevoir. If one failed, it would contaminate the other.
All of those circles and lines mean something. A circle with arrows pointed out means its a pump. One arrow means single direction flow, two arrows means bidirectional. Arrows pointed in means its a motor. A line drawn through the circle means its a variable displacement pump or motor.
In this case, number 10 is the single pump for the hydraulic system. It is single direction flow, fixed displacement. Inside of the hydrostatic transmission is a bidirectional, variable displacement pump and a bidirectional fixed displacement motor.
Also, it would be important to point out that the transmission and the hydraulic system are not separate. According to the schematic, both use a common filter and oil resevoir. If one failed, it would contaminate the other.
rdsaustintx
Veteran Member
OK I buy it, just from the motor shaft shown on the schematic going into the HST. But not from the note. I trust the diagram more than the Kubota translators.
Some of the stuff I read comparing SCUTs way back talked about two pumps on the JD. I guess it meant different reservoirs and sumps.
Soooorrry
Some of the stuff I read comparing SCUTs way back talked about two pumps on the JD. I guess it meant different reservoirs and sumps.
Soooorrry
Volfandt
Veteran Member
In MHO, I think when most manuf's indicate two or more pumps, they mean implemant and power steering pumps and not the HST's pump & motor.
Some will have one pump for the implements and another for the power steering whilst others will have separate pumps for the FEL, PS and BH for a total of 3 not counting the HST. Commercial units may have 4 or more.
In the case of the BX's, they have one implement/PS pump (useing a priority valve) and of course the HST has it's own.
re. the OP's problem, a pressure check will take the guess work out of it.
Good luck
Some will have one pump for the implements and another for the power steering whilst others will have separate pumps for the FEL, PS and BH for a total of 3 not counting the HST. Commercial units may have 4 or more.
In the case of the BX's, they have one implement/PS pump (useing a priority valve) and of course the HST has it's own.
re. the OP's problem, a pressure check will take the guess work out of it.
Good luck
quarencia
Silver Member
Interesting discussion. Technically, the BX has two hydraulic pumps. The Hydrostatic transmission pump and the primary hydraulic pump. Hyper-technically, the oil pump in the engine is a third hydraulic pump. Insano-hyper-technically, there are also two fuel pumps that are technically hydraulic pumps.
Insanity aside, in general tractor lingo, I agree with volfandt. Typically, the HST pump is not referenced as a hydraulic pump when talking about how many pumps a tractor has.
In the case of the BX series, there is one primary hydraulic pump that supplies all hydraulic fluid. This includes the fluid to keep the HST full. The primary hydraulic pump puts out about 5.5 Gal/min unloaded at full speed. The flow diverter maintains about 3.3 gal/min to power steering and HST at all times with the rest going to implements and 3ph. That's why at idle implements won't move. All flow is being diverted to power steering and HST.
The hydrostatic transmission pump and motor are a self contained unit. Meaning the HST pump sends fluid to the HST motor and it loops directly back to the HST pump. The HST pump does not draw fluid directly from the reservoir. Additionally the HST pump and motor do not dump fluid directly back to the reservoir in the transaxle. Small amounts of fluid that "leak" past the piston seals in the HST pump and motor flow back to the reservoir. This is by design. The primary pump supplies fluid to make up for this bypass as well as keeping positive pressure on both the input and output side of the HST pump in either forward or reverse. Without the primary pump, the HST would slowly drain all fluid and stop functioning correctly. The HST can not work without the primary pump.
A one pump tractor almost always has a flow priority valve splitting flow between the power steering/HST loop and the implement loop (if a tractor has Power Steering and HST). Two pump tractors have a pump on a dedicated loop for power steering and HST with the second pump on a separate dedicated loop for implements. The advantage of two pumps is consistent performance of hydraulic implements independent of demand from Power Steering and HST. Additionally, the complex flow priority valve is eliminated. On the down side, more pumps and more plumbing add cost.
As volfandt noted, as equipment gets bigger and functions get added the number of pumps keep going up.
OK, I've rambled enough.
Insanity aside, in general tractor lingo, I agree with volfandt. Typically, the HST pump is not referenced as a hydraulic pump when talking about how many pumps a tractor has.
In the case of the BX series, there is one primary hydraulic pump that supplies all hydraulic fluid. This includes the fluid to keep the HST full. The primary hydraulic pump puts out about 5.5 Gal/min unloaded at full speed. The flow diverter maintains about 3.3 gal/min to power steering and HST at all times with the rest going to implements and 3ph. That's why at idle implements won't move. All flow is being diverted to power steering and HST.
The hydrostatic transmission pump and motor are a self contained unit. Meaning the HST pump sends fluid to the HST motor and it loops directly back to the HST pump. The HST pump does not draw fluid directly from the reservoir. Additionally the HST pump and motor do not dump fluid directly back to the reservoir in the transaxle. Small amounts of fluid that "leak" past the piston seals in the HST pump and motor flow back to the reservoir. This is by design. The primary pump supplies fluid to make up for this bypass as well as keeping positive pressure on both the input and output side of the HST pump in either forward or reverse. Without the primary pump, the HST would slowly drain all fluid and stop functioning correctly. The HST can not work without the primary pump.
A one pump tractor almost always has a flow priority valve splitting flow between the power steering/HST loop and the implement loop (if a tractor has Power Steering and HST). Two pump tractors have a pump on a dedicated loop for power steering and HST with the second pump on a separate dedicated loop for implements. The advantage of two pumps is consistent performance of hydraulic implements independent of demand from Power Steering and HST. Additionally, the complex flow priority valve is eliminated. On the down side, more pumps and more plumbing add cost.
As volfandt noted, as equipment gets bigger and functions get added the number of pumps keep going up.
OK, I've rambled enough.
tractorman
Silver Member
It looks like two pumps to me.
MoreCowbell
Silver Member
This is why this is such a great site. You can find info, like that in this thread, that would be hard to find anywhere else.:thumbsup:
I have one question. Would the hydraulic schematic that Rdsaustintx posted apply to my BX2350 as well? (Minus the BH control valve of course).
Thanks.
I have one question. Would the hydraulic schematic that Rdsaustintx posted apply to my BX2350 as well? (Minus the BH control valve of course).
Thanks.
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