vermeer 252 creep

[jhg]

My 252 has 1677hrs on it. Lately I have been fighting its tendency to creep- either direction depending on the slope. If its headed down (toward the cutterhead), it is very hard to control and can actually lunge into a cut, either before its pulled in by the cutting action, or simply by gravity at any time. So I position uphill any time I can and use the forward lever to compensate.

The chain is tight. New belt on the hyd pump and tensioned correctly. I know how to grind and do not overfeed the machine. Sharp teeth always (its a 252 w/25hp after all!)

Any suggestions where to start appreciated. Hope I do not need a new drive motor. Or can they be rebuilt?

Joshua

 

[equipmentguru]

The proper way to figure out what hydraulic component is causing the issue would be to take your machine to your local Vermeer dealer or someone who has the proper hydraulic diagnostic equipment to properly diagnose the malfunction. It can get very expensive if you start replacing hydraulic components. If you don't have the proper training and experience you can cause further damage to your machine or yourself. Some hydraulic mishaps can even be fatal. Be careful.

 

[Bigstumps]

Could be internal leakage in the hydraulic motor - this will allow the motor to rotate even if the valve is closed.

You can take the hoses off from the motor and cap the motor - then see if you can push it - if you can you know the fluid is being bypassed inside the motor and you need a new one.

If it can't be rolled you know the motor is holding and the problem probably lies elsewhere. They may have some type of holding valves between the control valve and the motor. These are usually counterbalance valves and are designed to hold the fluid in the circuit.

Trace the hoses from the motor ports under the machine back up toward the control valve. If there is another valve block in there these are the holding valves.

You could get a schematic from Vermeer. It would show what is in the circuit.

I find they all creep more as they get older and the clearances in the motor get bigger.

 

[jhg]

Thanks Bigstumps. That is the kind of information that is helpful. I will check the motor for movement and go from there.

Joshua

 

[equipmentguru]

There are 2 counterbalance valves for the ground drive motor. Capping the motor ports might work. There are only a number of components that could cause this issue. The directional control valve, which is the valve with the control handle; the counterbalance valves or the drive motor.

 

[jhg]

Thanks for that guys. I have not had a chance to check it out yet, but this gives me all I need to get things started.

BTW, if it does turn out to be drive motor related, couldn't a similar rpm motor be fitted that also has an internal brake? Would I be gaining anything by doing that, rather than fitting the same spec motor?
Also, the directional control valve may need attention anyway. Its not the most forgiving lever on the machine at the moment. Very touchy.

Joshua

 

[equipmentguru]

If it is the motor I would suggest replacing the motor with the same type of motor. Typically a motor with a brake requires more hydraulic hoses to be plumbed into it to apply hydraulic pressure to release the brake. You will most likely have to do some fabrication to make that motor mount and work. I am pretty sure that type of motor is more expensive. It could turn into a nightmare. Good luck