753 Bobcat Drive problem

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Jerv753

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Oct 13, 2022
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9
My right side drive when I'm sitting in it won't go as fast as my left side and when I try too turn it won't turn then all the sudden it will jerk then it will turn. Any ideas anyone? Is it possibly the drive motor? THANKS
 

brdgbldr

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Jun 1, 2012
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1,261
To me it seams more like a valve not opening all the way or something blocking flow.
 

brdgbldr

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Jun 1, 2012
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Any ideas where to start? It doesn't have the inline filters on it either
I would start by checking all linkages, if you have manual controls, for anything loose or any damage or cracks.

Take a look at the control valve and make sure everything looks good and nothing is loose or sticking.

If you have electronic controls you could have a bad connection, short, bad solenoids or the controls could just be worn out. This is a lot harder to diagnose but you can still take a look at the control valve. After that you have to start testing solenoids and controls.
 

Ster1

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Feb 8, 2022
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90
What's the engine doing while this is happening? Is it running normally, is it laboring, any indication it's fighting pressure? Does this happen from a standstill, rolling? Any difference in direction? Does it travel forward and reverse normally otherwise, even of you have to compensate? Does this happen every time, if not, under what conditions does it happen vs conditions it does not happen? When did this behavior start? Did it start suddenly or gradually over time? Did you do some maintenance and then it started? When was the last time you changed your fluid and filters?

The more info you can give us, the better chance we have of giving a meaningful response.
 
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Jerv753

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Oct 13, 2022
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9
The engine stays the same. It doesn't seem likes it's fighting pressure. Only happens when I'm moving. When it warms up it gets worse the motor stays reved up but it don't seem to have much drive. It happens every time. It started a year ago and steadily got worse. Rebuilt the drive motors last year. But it started b4 they were rebuilt. Ive changed the filter b4 winter. Got a couple small leaks by a couple hoses
 

Ster1

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Feb 8, 2022
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90
Assuming there are no trouble codes, and your BICS module is not showing activated ( I believe you have BICS on that machine?), I'd refer you back to what brdgbldr was talking about. If your boom is working properly, that usually means your charge pressure is ok, but never hurts to check that too. Sounds to me like you got a solenoid that's not working, or not working all the way at least. Do you have the book for this machine?
 
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Jerv753

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Oct 13, 2022
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9
Assuming there are no trouble codes, and your BICS module is not showing activated ( I believe you have BICS on that machine?), I'd refer you back to what brdgbldr was talking about. If your boom is working properly, that usually means your charge pressure is ok, but never hurts to check that too. Sounds to me like you got a solenoid that's not working, or not working all the way at least. Do you have the book for this machine?
This may sound dumb but which solenoid?
 

Ster1

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Feb 8, 2022
Messages
90
Sorry it took so long, I got a cold or whatever that just laid me out. Anyway, I'm alive again. So a 753 is a linkage machine. I wasn't sure when I mentioned the solenoid bit. There is a direct mechanical connection between your levers and the valving on the hydrostat. I'd start with making sure those linkages are set up right. Then just cuz I'm me, I'd double check that charge pressure. At that point, since you've replaced the drive motor, there really isn't anything left but the hydrostat itself.

I had a Gehl in once that had bizarre drive problems. It turned out to be a control arm that had a broken weld inside the valve block on the hydrostat. I had to remove the valve block, take it apart, re-weld the control arm, and Bob's your uncle. That was a new one on me.

If you haven't done so already, get the book. They usually have a good troubleshooting section at least that might help.
 
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Jerv753

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Oct 13, 2022
Messages
9
Thank you everyone for trying to help.
I figured it out the drive motor was bad
After it would warm up the drive got worse so I replaced both motors and it works fine . If anyone pulls a motor out that seems week try to turn the shaft and if it moves easily the motor is probably bad cuz the knew ones I got I couldn't spin them they are suppose to be tight. Thx everyone
 
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