Hi. I am new here and need some help. I have a 753 1993 model. The booms powers up quickly, but doesn't go down. The tilt is strong downward but won't curl back up. The machine has no problems driving, turning etc. I tried isolating the boom cylinder by raising it all the way up and removing the top hose for downward pressure, but when I started the machine fluid came pouring out immediately even without touching the pedal. The pedals and linkages appear to be okay and not out of adjustment. I don't bleive it's the cylinders because the boom stays up all night and next day without dropping. I'd like to add that when pedals are in nuetral the machine's hydraulic noise seems to be more labored than when I press the pedals. It seems the machine doesn't labor at all when pedals are depressed. I hope someone has experience with this and is willing to help me. thanks for reading. Scott.