It takes time to get the pump primed and pumping oil. Have patience and keep at it. You'll hear it when it starts to bite.

If you lubed up the pump when you reassembled it, give it a minute or two at half throttle and full stroke on the drive control.

If you didn't lube the pump, open it up and do so. Hydraulic pumps will pump air if there is oil in them to create a seal. They just don't pump air as well as they pump oil and it takes quite a bit longer.

 

Thanks for the tips. I did not fill the pumps with oil before reassembling, so maybe that is my problem. I'll crack it open (again) and do so.

 

I was really hoping that I didn't have to open it up again, so I thought I'd try the purge again.

I removed the transmission and put it on my bench. I then used my electric drill again to spin the pulley while I used a wrench to have it go forward and backward (with and without the bypass on). I could see the axels turning, so I went through the procedure twice.

I mounted it back on the tractor and did the purge again on jack stands. It took a while, but I managed to get the wheels to start rotating. I removed jack stands, and it still did not go anywhere, until I gave it a nudge forward, and the tractor started moving. If I stopped, then it would need another nudge to go forward again. It wasn't all that fast either.

I had to go inside at that point, but I was happy that at least it started moving again. I'll try the purge on jack stands again tomorrow to see if I can get more air out.

 

NEVER assemble any mechanical drive components without using an ample amount of the proper lubricant, especially hydraulic components. There is no such thing as "too much lubrication" in hydraulics!

After you squirt some oil into the pump, close the bypass. Set the drive control for a direction and clamp it in place. Turn on the drill. Go enjoy a beverage.

It takes time to pump out the air. Twiddling with the controls every few seconds will not get the job done. It takes a minimum of 30 seconds and could take several minutes using a drill.

If it doesn't bite in 10 minutes, there is probably an assembly problem, but the pump won't be damaged from running that long because it was adequately lubed before the process was started.

 

I did the 30 seconds of forward then 30 seconds of backward 5 times in both bypass and engaged mode. That seemed to fix my issue.

I assume temperature has an effect too. I assume the viscosity will keep the air bubbles longer at a lower temperature than at a higher temp. It was close to 60F today, and it seemed to go smoother.

Thanks again for the help.

 

The air bubbles will disipate in short order.

 

Once the air is displaced in the hydro- Check your level and add more oil if needed!