I have a 4530 4wd T2.  Today when I tried using the tractor, the box blade wouldn't lift.  When turning off the ignition the blade immediately raised about 3 inches. In order to get it fully raised, I had to turn the tractor on and off.  It lowers fine and all other hydraulic functions work.  The fluid is also fine.  I fiddled with the control knob below the seat but that did not have any effect.  Any ideas before I try to open this baby up?
	
		
			
		
		
	
				
			 
 
		