Hello, new to this forum, thought I would run this by some people that might have some experience with this tractor. A friend was handed the tractor down to him from a family member. Complained that it howled when trying to steer but boom and bucket hydros seemed to work fine. We drained the hydraulic fluid, replaced some hoses and o-rings that were leaking, and changed the 10 and 25 micron filters. Refilled with fluid, as per the manual he has. The problem seems to be only on the left side drive. The boom and bucket operate ok, and the right side drive seems ok also. The left side seems not very responsive, it doesn't want to move until you give it almost 1/3 stick movement, then it jerks and moves. Not smooth at all like the right side. Also if you try to move the left only, slowly, it will trip the filter light. When you are traveling at full foward, it also seems to walk to the left weak side. Any help would be appreciated.
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700 is a really old skidsteer. I'm not sure if the owner is correct on the year but, he said it was a 1964? I wasn't aware that they were making anything like this back then. I thought it was a typo for 1984. But he's telling me it's a 64. Anyways, the manual he has shows 700's and 720's in it, if the 720 series is more familiar.
Is it hydrostatic drive?
It could be a worn rotating group or wear plate on that side causing it to be less responsive. This can be fixed if its just a little worn with a sheet of glass and wet and dry sand paper.
The drive motor may also be a little worn, there are lots of possibilities. Even something as simple as a lose linkage?
It is hydrostatic drive. The linkage at the levers is a little worn. But it seems pretty equal between both sides. When I watch the pivot at the pump it seems to move pretty solid compared to the right side that seems to work normal. I almost think it is either in the hydrostatic pump or the hydro motor on the left that seems to lazy. Is there any way to test the pump or the hydro motor on one side only to see if one component is bad? When I push on the lever it doesn't move, then all of the sudden it jumps, not smooth like the other side. Also if I progressively push it slow, it will trip the filter light, like it's losing pressure. Thanks for the points to check. Let me know if there is a way to check the pump or motor on the left side compared to the right.
Tazza, when you are talking about the rotating group, and wear plate, are you talking about the vanes in the pump not sealing to the housing? If not, could you give me a little insight on what those components are and how to check them? Thank you very much!
The rotating group and wear plate is part of the pump that feeds oil to the hydraulic motors. The have no vanes like the hydraulic pump has, it uses pistons, don't mind the rust, this was from a damaged unit:
You could swap drive motors from side to side to see if the problem moves with it. If it moves, the problem is in the motor, if not, the problem is the pump. The pumps and motors aren't that hard to work on either, just keep them clean clean CLEAN.
Tazza, alright, thanks for the pic. I guess I'll swap the motors like you said and try to narrow it down that way. Is there a way I can test hydro pressure at the motors or is swapping the easiest way? Flyerdan, this machine is not mine, but it does have a gasoline powered air cooled v4 engine.
To test it, you need a propper test unit to measure pressure and flow.
Testing pressure at the motor won't tell you much, you need both flow and pressure to tell the condition of the pump. It may be generating the full 5,000 PSI but the flow rate may be way down.
