Logmax 4000b knife problem.

[Osvaldas1991]

Hello, any ideas why top knifes dont have to much power keeping timber when its close. And when i full open they slowly closing.

[Gary_C]

I don't know Logmax but what you describe is usually a sign the knife cylinder packing is leaking.

[mike_belben]

Put the hoses to the cylinder into a clean bucket or gas can, put your glasses on and have an operator stroke the valve both ways while you watch the flow volume and intensity.  Thatll atleast give you an idea if youre issue is upstream [valving or delam'd hose] or downstream [cylinder] of that point.  If youre lucky maybe a piece of trash will blow out. 

[Don P]

Pull off the hose at one end and stroke the cylinder. If it empties the oil that is in the open end of the cylinder and then continues to dump oil the packing is blown.

[Skeans1]

The safer way would be plug the line and see if you build pressure if you do it's a cylinder issue, if not you have thrash in the compensator.