Got a little bit of snow in Nebraska today. Went out and hopped into the trusty but rusty 75 chev. Fired right up, Lifted the blade and drove out to the drive. Dropped the blade and the was the last time it moved. The motor runs, but the blade will not lift or angle. I can grab the lift piston by hand and move it easily up and down one or two inches because of the slack in the chain. If feels as if there is no suction behind it. Fluid level is ok. Hydraulic hoses are new. Any Ideas???