656 Hydraulics-The saga continues

[Scott(MO)]

Well, I pulled the pump yesterday and found a sheared key. I put the pump back & put fluid in....nothing.I drained the fluid, and pulled the pump expecting to see another sheared key, but no....the drive gear still had the key Not sure where to go from here!

 

[kossuth]

(quoted from post at 13:42:19 12/22/20) Well, I pulled the pump yesterday and found a sheared key. I put the pump back & put fluid in....nothing.I drained the fluid, and pulled the pump expecting to see another sheared key, but no....the drive gear still had the key Not sure where to go from here!

he fact it had a sheared key is telling. While I am no expert on a 656 hydraulic system Id place money on something jamming the pump up. Depending on where your located my first guess would be ice.

 

[used red MN]

Did you check to see if the 3 point a PS came back? I don’t know if the sheared key stops both pumps or only one. Since you pulled the pump I wonder if you may have accidentally got some debris in the system that made its way into the relief valve?
Original post on saga

 

[Janicholson]

Jim's idea. With it jacked up as before, and the plate off, see if you can loosen the pumps well enough to see them turn. (shaft or?) then put it in 5th and TA forward. turn the wheel that is up and see if they turn! At least you will have a start at diagnosis. Jim

 

[Scott(MO)]

Well, I thought the same thing about something jamming the pump as to why it sheared. But I can spin the pump by hand OK and I doubt it is ice as it has been in the mid-50's the last few days and I see no traces of water in the system either.

 

[Scott(MO)]

there was a little movement in the 3 point, but slow and sluggish (almost non-existant). I worked on bleeding air from the system, to no avail. I already thought about the relief valve and had it apart and back together this morning...nothing wrong there. ???

 

[Scott(MO)]

I will see what I can do tomorrow.

 

[Roger Tomfohrde]

OK if you pulled the pump and cover to change the key you likely don't have tube seal in the middle in the right place and are now sucking air instead of oil. Also could have broken the gear inside the pump.