425 Need help

[MossRoad]

I just came across my PDF copy of the drive pump manual. Provided they are still using the same pump, which seems likely, the specs call for +/-15 degrees max rotation for the control shaft that is operated by the treadle.

The control shaft operates an internal swashplate that controls direction and flow of the pump's output. The manual states that the control shaft has no internal spring or other centering device, and that internal forces may move the control in either direction, therefore the control system must hold the swashplate control shaft at the desired angle.

I read that to say that a sloppy or loose treadle control could result in erratic operation.

Does he have the hydraulically controlled treadle? If so, how can he check that as opposed to the cable controlled treadle that we have?

 

[SnowRidge]

Does he have the hydraulically controlled treadle? If so, how can he check that as opposed to the cable controlled treadle that we have?

On ours, you can grab the arm on the shaft and try and turn it against the treadle. It won't budge. His shouldn't, either. Of course, you should also operate the treadle to make sure the control is moving the full +/- 15 degrees. He should be able to do the same thing on his machine with the hydraulically operated controls.

It may or may not take two people with his machine, because of the different layout. On ours, one person can do it. It only takes a few seconds to check.

Maybe somebody with the hydraulic treadle and newer layout will chime in and comment.

 

[Central_PA_Chris]

OK, Terry walked the shop through the trouble shooting process (every attempted fix did not solve the problem) then had them remove the hydraulic pump that drives the wheels and ship it back to them, so the repair is in motion!