I have an old Bobcat 630 that won't lift. It worked fine one day and the next day wouldn't lift. I checked the fluid and it was low so I added more but it still wouldn't lift. I took off the seat to check the pedal connections and they are fine. I noticed these little pistons/cylinders that the pedals were attached to. The bucket tilting piston moves in and out fine. The bucket lift piston seems to be stuck and will not move in and out. Any suggestions?