TC33D hydro problem

[ranger15]

Tractor had been sitting, came in as a non-runner. Got it running(stuck rings), now it wont move under its own power. Hydro system flushed, fluid and both filters changed. Put a gauge on the test ports under the steering column, both show a max of 200 psi at 2000 rpm when the treadle is engaged in any range, the 3pt functions normally, brakes are not stuck. What is normal pressure and are there any other test ports? Thoughts? TIA

 

[CloverKnollFarms]

Sounds about 2,000 psi low

 

[oldnslo]

Not familiar with TC33 but are you sure the range selector is in gear?

 

[ranger15]

Checked range selector linkage 1st thing. Jacked up rear end to confirm and tested with no load. IT IS going into gear and IS NOT driving wheels even unloaded. I suspect either the hydrostat pump is not working or all pressure is being dumped. Is there a way to check without splitting the tractor? Is there a relief valve accessible without splitting? I have worked on a JD dozer with a similar issue (stuck relief valve) and got it to drive (sporadically) with a push from another machine,I plan to try this once help comes available. PS I am an experienced mechanic just have not experienced this particular system before.

 

[dfkrug]

Is there a way to check without splitting the tractor? Is there a relief valve accessible without splitting?

RV and test ports for HST charge pump, forward, and reverse should be accessible without splitting, but I do not know NH tractors. I have accessed them on JD, Kubota, Kioti, and McCormick. You should get a service manual. Worth getting, esp for hydraulic system.

Yes, stuck charge pump RV (300-500psi) can cause these symptoms.

 

[oldnslo]

Steering circuit should be separate from HST so those pressures are possibly normal for steering.

Like DF said there should be test port for charge pressure which would effect both directions of operation. Stuck high pressure relief would only effect one direction of operation.