1872 No hydraulics after pump reseal
 

I took the hydrostat rear end out and removed the hydraulic pump to replace the 2 trunnion seals leaking. Put the pump back on and changed the fluid and filter with Hytran and cub filter. Cranked it up and nothing moves. Took the pump back out to double check the charge pump was on right and the pin was in the gear and roll pin was in the driveshaft coupler. Everything inside the pump looks clean and no wear. Still no pressure. Check valves have been rebuilt. Linkage is setup and shimmed the slop out of it. New springs in the shift plate. Lines are on correctly. Marked them when I took them off. They can only go one way because ones longer and then the other. Read a post to charge it with air. Nothing. Read another to loosen the filter while running. When I did it shot fluid back up/out the dip stick tube. It was foamy/white. I suspect from the air shot treatment. Why would it shoot out the tube ? Any suggestions on what’s going on ?

Make sure you reinstalled the charge pump housing on properly.
There are 2 bolts holding it on,and one of those bolt ears has a milled end, the other is round and does not have a milled ear,-- or boss if you prefer.
If installed incorrectly, it will not pump.

If the charge pump is on correctly, and you disassembled the hydro,the valve plates in the hydro have to be installed correctly and not mixed up as there is only one right way to be installed.
They are easliy mixed up. :bigthink:

He mean this....

And then he mean this....

Double post

The hydro will still work at lower rpm’s and become progressively noisier as rpm increases, if the plates are switched. And eventually destruct.

I would let the oil settle then remove both release valves and slowly pour oil into each port while turning the input shaft by hand. Turn the shaft both rotations while feeding the port that is “sucking”. Reinstall the valves and try it. Do you have auto release valves or button release? Do you have access to other known good valves?

Dumb question, but did you put the pin back in the swash plate and trunion shaft?

The charge pump is definitely on right. I took it apart and checked the plates and were correct also. Gonna take it apart again and triple check the valve plates. Confused as to why it shot fluid out the dip stick hole when I loosened the filter while running.

I was wondering if you really have the correct filter even though you mention you have cub cadet filter. See this link:

https://www.onlycubcadets.net/forum/showthread.php?t=12

Well I’ve got the.Cub Cadet 723-3014 filter. I’m gonna change it again to see if that’s the problem. Thanks for the link.