S205 Jerky controls.

[spitzair]

Hello everyone, We have a 2008 Bobcat S205 here at work. It has the selectable hand or foot controls and just under 2000 hrs on it. Lately we've been noticing that every now and again the controls get very jerky when using the pedals. My boss was loading stuff into his truck with it and the arms "Went berserk" according to him, they jerked up so much that they broke the back window in the canopy of the truck, and then when he went to lower the arms they whacked down on his tailgate... I wasn't there when this happened but he has been around equipment all his life and he knows what he is doing... Then the other day I was using the machine to backfill a trench and the arms slammed down all the way fast. I thought maybe I pushed the pedal too much but then it did it again with only slight pedal pressure... Another fellow operating the machine also noticed the same issue. Are there any known issues with these machines? None of us are proficient at using the hand controls so we don't know whether or not it does it with the hand controls too, and it has been very intermittent... Another thing to mention - my friend was using it the other day and said that when he got in to use it the lift arms didn't unlock but everything else did, so he shut it down, restarted it and pressed the "press to operate" button again and it worked normally after that... We need to get this issue resoled ASAP as we use the thing around aircraft and to move aircraft parts and having it behave this way is definitely a bad thing... We checked the pedal linkage for obvious problems, but it moves freely and is all clean (nice having an enclosed cab!).

 

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is there any chance the aux hydraulics get engaged by acccident? or maybe something is triggering them. when you engage aux hydraulics with no attachment on it the machine will go nuts.

 

[spitzair]

is there any chance the aux hydraulics get engaged by acccident? or maybe something is triggering them. when you engage aux hydraulics with no attachment on it the machine will go nuts.

Tom, not that I know of. I used the machine a bit last night and put it in hand control mode, and when I went to lift the arms up slowly they did move slowly, then when feathering the control to go faster it kept moving at the same speed then suddenly sped right up. Same with going down. The strange thing is when in hand control mode the bucket is actually a lot jerkier than in foot control mode when the bucket is as smooth and reliable as on my mechanical 873. When I used it this winter with a blade on it, it never acted up on the aux. hydraulics, I would imagine that if they got triggered the blade would have moved... I'm wondering if there's something down between the valves and the actuators that is causing grief, but I have no idea how that fancy electronic actuating system works. If I ever buy a new machine it's going to have the old school manual controls on it if they're still available...