6211 hydraulics not lifting to full height

[tractorcoleman]

Hi, i have a 6211 and it has never been any trouble it is only used for doing a bit of grass cutting. just recently the link arms wont lift to full height and will drop while in us when the tractor has been working for a while. The oil in the back end is fully topped up so that is no problem, and i have have checked the linkage on the lever and this is getting to full height but he arms will not come all the way up. Is there any way i can test the pump with gauges to see if its putting out full pressure and if so where can i do that?
Or does anyone have any other ideas what the problem may be?
Cheers
Chris

 

[alan]

Probally the change over pendulum slipping off the roller pin.

 

[tractorcoleman]

Hi, how do investigate this?
Cheers

 

[alan]

Take top cover off & look at linkage