John Deere F935 Just stopped moving

[treedigger]

I have a F935 that just stopped moving and lost all hydraulics while mowing. The mower was working fine and then just stopped moving. At the same time the steering stopped working and the lift for the deck stopped. Engine runs fine and pto works. Drive shaft is turning the charge pump. I have taken the charge pump out and checked it. I have not preasure tested it yet. I have to make a guage up. While it was out changed the seal, bearing, o-ring and pin. Inspected pump for wear and damage and everything looks fine. Checked and cleaned charge, implement and steering relief valves. I also changed the filter. I still have no hydro. Like I said everything was working great right up to the time it stopped. Any help or Ideas would be appreciated. Thanks

 

[beenthere]

:welcome:
Had some questions, but sounds like you are deep into this thing. I'd have done some psi checks before tearing the pump out, but that is just me.
No ideas at the moment. Do you have the tech manual?

 

[treedigger]

I do have the John Deere tech and repair manual. I would have checked the pump preasure first but did't have the right adapter to fit. It should be here Tuesday.Machine has alot of hours on it so I wanted to check the pump anyway. It is easy to to remove and install.

 

[treedigger]

I have finally had time to check my charge pressure. I have only about 15lbs. I have rechecked everything else again and it all looks fine. i think it is internal in the transmission. Anyone have any thoughts.

 

[Smally]

My mower just did the same. Did you find out what was the problem with yours.

 

[treedigger]

Sorry about not getting back to you to you sooner. Work has been crazy. The problem with mine was the transmission cylinder block for reverse wore out. The splines of the block wore and I was losing all my pump preasure. My mower has over 6000hrs on it so it was due.

 

[gelding703]

I just experienced the same thing with an 1988 F935 with 1300 hours on it which just stopped while mowing--no hydraulics, no movement forward or reverse. Immediately expected a transmission problem. Checked hydraulic fluid level and it was fine, no excessive heat, no burning smell. Crawled underneath to drain fluid and change filter to check for possible metal shavings and much to my surprise (and delight), the thick rubber "isolator" had broken apart and the two halves of the drive shaft were dangling under the chassis. Replaced the isolator (expensive at $130 at the dealer) and everything is fine. False alarm which might help someone else.