8/2/2013 5:08 AM
I would remove the cylinder and raise and lower it manually and see what happens. Even with the lube, the arm could still be binding up on you. if it works fine hook it back up and try it, when it starts to stop, crack your hydraulic line and see if it goes down, may have something clogging the port. My guess is you'll find the lift arm is getting held up a bit.
Regards,