BX23 HST pedal no pressure

[safar]

I have an issue with getting no pressure to the HST pedal (pedal is just limp and not working, can be freely moved up and down by hand)
It's a BX23, approx 1300hrs.
Just did a service (Engine oil, fuel filters, transmission oil and filters)

The tractor ran fine, reconnected the MMM, mowed for a bit all all was fine.
Checked the fluid levels and transmission fluid and engine oil levels were high, so I drained these to normal and it was still all running fine.


Went to connect the FEL, all hydraulics were working fine, got this connected, and went to drive it and the pedal was just limp (no pressure - I don't know how else to describe it) and I couldn't drive at all.
Disconnected the FEL hoses, checked fluid levels etc.
Reconnected the FEL hoses, raised, lowered and all worked fine, so I parked the bucket and disconnected the FEL hoses.

So, at this point, Power steering works, 3 point can be lowered raised, MMM lowered and raised, MMM turns on and works fine and just don't have any pressure in the pedal and cant drive it at all.
It seems to have happened right when I was working on connecting the FEL and lowering and raising it to get it lined up and connected.

Hoping to get some suggestions and ideas on what it could be or what to try. Thanks.

 

[valkyrie9901]

Any linkage come loose?

 

[safar]

Any linkage come loose?

I tried looking but don't see anything. It's parked in a weird spot where I went to connect the FEL and haven't been able to easily check underneath.
I don't have much experience with doing much more than the basic service, so not exactly sure what to look for in terms of loose linkage from the pedal. Would a WSM show this? I should purchase one.

 

[valkyrie9901]

I would try and find a parts catalog with an exploded view and see if and where any linkage is...JB.

 

[Paul Thornton]

Try Messicks for a parts breakdown

 

[safar]

Thanks - will get a parts breakdown ordered and take a closer look and see if anything looks loose on the linkage and start there.
Any other thoughts and ideas though on what else could be causing this?
I'm looking at the attached diagram, and if I understand correctly the Hydrostatic Transmission (11) is after the Oil Strainer (9) and Hydraulic Pump (10)
I did remove and clean the Oil Strainer and wonder if it could be anything there or the hydraulic pump.

If I understand how this works, the PTO, power steering etc would all work before the Hydrostatic Transmission. Is that correct?
View attachment 5-Hydraulic System BX23 pg5-m1.pdf

 

[check]

Paul Short has a video showing how the throttle linkage can come loose, and how to fix it. You just tighten or replace a certain nut, but it is hard to reach.

 

[Dave M7040]

Usually one end or the other of the speed control rod 050 has come adrift.

Try using a mirror to help you look.

Dave M7040

 

[Dave M7040]

Thanks - will get a parts breakdown ordered and take a closer look and see if anything looks loose on the linkage and start there.
Any other thoughts and ideas though on what else could be causing this?
I'm looking at the attached diagram, and if I understand correctly the Hydrostatic Transmission (11) is after the Oil Strainer (9) and Hydraulic Pump (10)
I did remove and clean the Oil Strainer and wonder if it could be anything there or the hydraulic pump.

If I understand how this works, the PTO, power steering etc would all work before the Hydrostatic Transmission. Is that correct?
View attachment 615851

Actually, your interpretation is not correct. The schematic is confusing

Of highest priority is the power steering and the priority valve #8 ensures the steering always gets what it needs.

The hydrostatic transmission is largely self contained as far as flow is concerned. It uses the one hydraulic filter and is supplied with a small amount of oil from the steering priority circuit.

2.1.2 Oil flow of hydrostatic transmission
The pump and motor are joined in a closed hydraulic loop and most of oil circulates within the main oil circuit. A little
oil lubricates and oozes out from the clearance between the moving parts of the case. Then oil in the main oil circuit of
the HST needs to be supplied enough to make this small loss up.
The oil from the power steering circuit flows into the HST for charging.
The charge oil aids smooth operation of pistons for pump and motor. The charge oil passes through the oil filter
cartridge to charge relief valve port. The rest of oil passes through the charge relief valve into the HST housing. And
overflow oil from HST housing return to the transmission case.

Dave M7040

 

[radioman]

there is two things that could cause the hst pedal to be limp. as others said the rod link from pedal to the rear connects to a plate that the hydraulic rams must have come off from the cotter tee that fell out. well.. the cotter tee is wrong term as kubota has there own spring clip thing , but concept is the same . needs a pin to hold the rod in. you really need to have the mower deck off to see as its your first time under there to understand the workings. the other possible is the adjustable nut that holds the spring down on the hst but still part of the link but not the rod must have came off which is impossible since its a locking nylon nut. again- the mower deck needs to be off to see things better. i am willing to bet im 99 percent sure its a linkage issue somewhere and getting the deck off is the first step.