[Bruce J]

Father in law has a 2305 that sheared the hydrostatic upper shaft on the pump. Broke the u-joint and fan on the shaft.
Replaced the u-joints, fan, hydrostatic pump case, upper shaft, bearing and seals. When adding fluid, I get fluid in the sight glass after adding about 3 gallons. 3 point works, power steering works and as soon you push the forward or reverse pedal the tractor will not move and sound like it is under a load. The weird thing is the fluid in the sight glass disappears. Adding more fluid, the fluid comes out the overflow. Have visually inspected the forward and reverse relief valves with springs intact and valve body inside moves. Took off the bottom two plugs on the hydrostatic pump center case and the two valve bodies are intact,, but will not move up or down.. (I don't know if they are supposed to).
Have drained and refilled the tractor just thinking there may be a air bubble or a hydraulic lock up, with no luck in tractor movement.
Looking for some help on attempting to locate the issue. The hydrostatic pump is a pretty straightforward rebuild, just do not know where else to look.

 

[KHodges]

Can't help with no movement issue, but once you fill the tranny until fluid is visible in the sight glass (engine off) it is full. It normally will disappear once the engine is running as it is circulating the fluid. When you shut down, it will reappear in the sight glass after a minute or two.

 

[Bruce J]

In this case, hydraulic fluid never returns into the sight glass. Its like the fluid is trapped somewhere.

 

[arlen]

It might just take awhile to get all of the air out. I can’t really think of anywhere that the fluid could go.

 

[Bruce J]

I'm sure the fluid level is fine, because it is not running on the ground. The issue is, no forward or reverse.

 

[BOBL]

It's a long shot, but you said everything works but fwd/rev, and the tractor strains. Did you check to see if the brakes are locked?

 

[arlen]

I'm sure the fluid level is fine, because it is not running on the ground. The issue is, no forward or reverse.

I guess I was confused by your statement that the fluid never returns to the site glass when you shut it down. It would seem to me that you would need to keep adding until that occurred.
Everything rolls and spins freely in the drive train?
What caused the pump to break the shaft to begin with?

 

[Bruce J]

Thats the question, what caused the shaft to break? And yes the brakes are not engaged

 

[Bruce J]

I added oil to the tractor until it came out of the breather or overflow on top of the axle and there was never fluid in the sight glass.

 

[rtgt]

It sounds like something is blocking the return of the fluid to the tank.

You might need a hydro schematic / flow diagram to figure this one out.

 

[arlen]

The sight glass is probably full. Sometimes it’s hard to tell the difference between nothing on the site glass and over the site glass. Sounds like you better start looking at the drive train aft of the tranny

 

[RDR]

Father in law has a 2305 that sheared the hydrostatic upper shaft on the pump. Broke the u-joint and fan on the shaft.
Replaced the u-joints, fan, hydrostatic pump case, upper shaft, bearing and seals. When adding fluid, I get fluid in the sight glass after adding about 3 gallons. 3 point works, power steering works and as soon you push the forward or reverse pedal the tractor will not move and sound like it is under a load. The weird thing is the fluid in the sight glass disappears. Adding more fluid, the fluid comes out the overflow. Have visually inspected the forward and reverse relief valves with springs intact and valve body inside moves. Took off the bottom two plugs on the hydrostatic pump center case and the two valve bodies are intact,, but will not move up or down.. (I don't know if they are supposed to).
Have drained and refilled the tractor just thinking there may be a air bubble or a hydraulic lock up, with no luck in tractor movement.
Looking for some help on attempting to locate the issue. The hydrostatic pump is a pretty straightforward rebuild, just do not know where else to look.

Father in law has a 2305 that sheared the hydrostatic upper shaft on the pump. Broke the u-joint and fan on the shaft.
Replaced the u-joints, fan, hydrostatic pump case, upper shaft, bearing and seals. When adding fluid, I get fluid in the sight glass after adding about 3 gallons. 3 point works, power steering works and as soon you push the forward or reverse pedal the tractor will not move and sound like it is under a load. The weird thing is the fluid in the sight glass disappears. Adding more fluid, the fluid comes out the overflow. Have visually inspected the forward and reverse relief valves with springs intact and valve body inside moves. Took off the bottom two plugs on the hydrostatic pump center case and the two valve bodies are intact,, but will not move up or down.. (I don't know if they are supposed to).
Have drained and refilled the tractor just thinking there may be a air bubble or a hydraulic lock up, with no luck in tractor movement.
Looking for some help on attempting to locate the issue. The hydrostatic pump is a pretty straightforward rebuild, just do not know where else to look.

Did you ever figure out this issue? I am having same issue