7254 Hydrostatic Transmission pump question suggestion

wildfire · #1 02-18-2026, 03:57 PM

Hey all,

So I got the Transmission Hydrostatic Pump out, cleaned up, and reassembled. The charge pump looked great all things considered ( See below )

The pump shaft turned nicely as well, outside looks good, nothing out of the norm to report there.

I put it all back in the tractor, 2 new filters, inside cleaned and filled back to full with fresh oil.

On start, everything sounds good, the pump is not making any funny noises. Shifting the pedal from forward to center to back you can hear the change in fluid moving. After about 10 minutes, the pump and oil lines are getting warm so it appears fluid is moving.

That said, I am not getting any movement in the axel. Shifting from high low neutral is working as expected but I can hand spin the wheels no mater what gear. I read that sometime the lines need blead with some air pressure from the fill hole, gave that a try but no change in behavior.

The pump is also not engaging / spinning the outboard shaft to spin the gears to power the Steering and Auxiliary pump ( took a peak under the top plate while it was running ). Below is a video of when I took a peak, I apologize in advance for the rattle noise, its the heat shield on the muffler.

https://drive.google.com/file/d/1LXL...viNi5v5sA/view

I am about to place an order to get a pressure gauge to see what the pressure is at the charge pump as per the service manual. Wanted to see if anyone had ideas to "Check" before I assume the pump is toast and start looking into rebuilding or replacement research.

A side note, there is a electrical issue, the key currently only powers the oil light and fuel pump, I have to jump the coil to start it and wait till its outa gas before she shuts off. Don't believe there is anything electrical that would prevent the pump from working but wanted to throw that out there just in case there is. Got a switch on order which will start the electrical journey into this project.

Thanks again all for your time!

wildfire · #2 02-18-2026, 04:27 PM

I should also mention, I put the Charge pump back on the orientation that it was on disassembly BUT there was no bolts holding in place when I started so there is a chance that the previous tinkerer did not put it on correctly.

Is there any guide / trick to verify that the charge pump is indeed oriented correctly?

DeltaCub · #3 02-18-2026, 04:43 PM

The splines on the hydro output shafts are in poor condition. The corresponding gears are probably just as bad if not worse. Many parts for this series are very difficult to source. These tractors were poorly engineered and were produced for a short time. I am speaking from experience as I inherited one of these bastards. Maybe our sponsors can help you source the parts you need. I wish you well.

wildfire · #4 02-18-2026, 05:17 PM

I appreciate the feedback, I know the parts are hard to source, I took this on for that challenge. If I get to the point where I need to replace a part that I can't source, that's when I plan to say game over. I found a vendor to replace the entire pump but don't want to entertain a 1500 dollar part until I exhaust other thoughts :-)

That said, the splines looks bad because of the amazing red dirt here in north texas. Cleaned up they didn't look so bad, not perfect but I think are in a ok condition. The gears on the inside were in great shape, will get a pic for those to add to the chat today / tomorrow-ish

That said, I just realized from my post and recapping myself that there was no shaft pin for the charge pump which I can't believed I missed. Explains why it was so quiet.

Is that pin source-able without an entire kit?

wildfire · #5 02-18-2026, 07:01 PM

@DeltaCub you might be onto something. I drained and pulled the pump out partially to take a look inside where the shaft meets and either it was not in all the way due to the spacers or its stripped and didn't look as good as I thought.

Will take it out the rest of the way tomorrow and keep you posted. Thanks again for pushing me to get it back out!

Sam Mac · #6 02-18-2026, 08:10 PM

Quote:

Originally Posted by wildfire

I appreciate the feedback, I know the parts are hard to source, I took this on for that challenge. If I get to the point where I need to replace a part that I can't source, that's when I plan to say game over. I found a vendor to replace the entire pump but don't want to entertain a 1500 dollar part until I exhaust other thoughts :-)

That said, the splines looks bad because of the amazing red dirt here in north texas. Cleaned up they didn't look so bad, not perfect but I think are in a ok condition. The gears on the inside were in great shape, will get a pic for those to add to the chat today / tomorrow-ish

That said, I just realized from my post and recapping myself that there was no shaft pin for the charge pump which I can't believed I missed. Explains why it was so quiet.

Is that pin source-able without an entire kit?

If you didn't have the pin in the charge pump it won't pump so that would explain why it wont move. You may be able to get a pin from the manufacturer of the pump or measure the size and try McMaster Carr.

wildfire · #7 02-18-2026, 09:18 PM

Quote:

Originally Posted by Sam Mac

If you didn't have the pin in the charge pump it won't pump so that would explain why it wont move. You may be able to get a pin from the manufacturer of the pump or measure the size and try McMaster Carr.

I know, I feel quite dumb, I just put it back together as is, didnt even think about asking myself if anything was missing. I might shoot Messicks a note with a length to see if its something they on shelf as a loose item or know if a manufacturer to contact.

McMaster Carr is interesting too, I'll try to find more info about this pin so I can inquire a safe aftermarket replacement for it.

wildfire · #8 02-19-2026, 03:22 PM

DeltaCub was sadly right on the money.

Once all cleaned up, its definitely worn down pretty good on the pump and the PTO shaft looks pretty toast. I shoulda cleaned that up and inspected a bit better before shoving it all back together the 1st time

I need to size the pin so next on my list is to make a temp dowel for sizing and reinstall temp and run the pump with a drill just to make sure the old girl can move before I dig deep into the shaft issue.

Messicks has the shaft for 400 shipped but going to look around a bit more 1st to see if I can get lucky with a used. Also might talk to a local machine shop here to see if there is something custom we can do.

Always open for interesting suggestions as well

Sam Mac · #9 02-19-2026, 08:42 PM

I did a little digging your pump looks like the 15U series pumps in the GT's except for the output shaft so i looked up the part for a Cub 2182 pump. The pin is available from Messicks (part # 30,SU-9004875-0076 ) $42.58

https://www.messicks.com/catalogs/cu...n/transmission

I also looked up 15U series charge pump drive pin on Google and found this for$4.99

https://www.savepromofy.com/product-p-900852.html
15 SERIES CHARGE PUMP DRIVE PIN SAUER SUNDSTRAND DANFOSS HPX-9004875-0013

Now I can't be sure if they will fit but for $5.00 it's worth a shot.