Hydrostatic "slipping"?

[vtwoodchuck]

Hello:
I have an L3700 SU. Its three years old with 60 hours on it. I use it for light logging, sugaring and brush hogging. The tractor has lost its ability to climb even the slightest incline. The hydrostat squeals as usual but does not climb even in low range. I does seem to climb better when going backwards. The loader does not seem to have lost its power.
I have changed fluids and filters using Kubota fluids. The loader filter had metal filings in it.
The condition is getting worse over time. I have a good dealer an hour or so away but would prefer take a look myself first.
Thanks in advance for your thoughts and help.
Chuck

 

[Bulldog]

Did the problem start after the fluid was changed or was it already acting up before that?

How does the fluid look now?

 

[vtwoodchuck]

Did the problem start after the fluid was changed or was it already acting up before that?

How does the fluid look now?

Ha ha, excellent questions. I definitely started after the filter change but, I did not notice until a while after. It has been getting worse. I changed the filters in february and it seemed fine then. I was also working in a much colder environment. I strained the fluid before re using and found some metal (aluminum ) in the screen. Color....dark amber.
Im thinking I will start all over with new fluid and filters. Does that seem correct?
I guess I was thrown for a loop when I found it climbs well in reverse.
Thanks for your help.

 

[Bulldog]

I just can't see the fluid being that bad unless it has been really overheated in a hard pull or something like that.

Does the fluid look foamy like it has air in it?

 

[vtwoodchuck]

Bulldog:
Im and old 8N-9N guy so hydraulics are not my strong suit.

I.ve never worked this tractor hard. I run a Farmi on it through the winter so rarely drag big weight.

No foam. Metal shards were in the loader filter and not the main filter. I adapted a snow plow to angle using the bucket controls and thought the shards were from that.

Any thoughts on why it climbs better in reverse?

I appreciate you time and help

 

[Express]

I'm real new to tractors but from reading some forums I heard of some similar issues with HSts. Some one else had a issue with the HST regulator bypassing fluidvwhen in certain pedal positions. It's just a metered valve the directs the fluid direction and pressure with pedal travel. Again I'm new to this. Hope this helps

 

[vtwoodchuck]

I stopped by the dealer today to pick their brain. The sales guy was thinking linkage, the service guy said that it is under warranty.
I'll bring it down Friday.
It always feels like a cop out to have someone else fix it. Ill keep you posted.

 

[vtwoodchuck]

I'm real new to tractors but from reading some forums I heard of some similar issues with HSts. Some one else had a issue with the HST regulator bypassing fluidvwhen in certain pedal positions. It's just a metered valve the directs the fluid direction and pressure with pedal travel. Again I'm new to this. Hope this helps

Some good info there. Thanks Express.

 

[vtwoodchuck]

I stopped in at my dealership. They called the factory rep in to check it out. 700 PSI forward, 4800 PSI reverse. They are gonna tear into the main unit.
Im kinda disappointed that I am having a "major" issue with 90 hours on it...

 

[SteveF]

Is there a strainer on the return suction that can be cleaned?

 

[hodge]

I stopped in at my dealership. They called the factory rep in to check it out. 700 PSI forward, 4800 PSI reverse. They are gonna tear into the main unit.
Im kinda disappointed that I am having a "major" issue with 90 hours on it...

It's a machine, and a complex one at that. Don't be discouraged, be relieved that it is under warranty. It can happen to any brand, at any time.
It isn't common- most Kubota's run great from the start, for thousands of hours. It isn't indicative of a bad tractor brand.