Hello, I recently bought a 1991 L783. Well used, i notice it makes a squealing sound when controls are pushed all the way forward or backwards. Hydraulic fluid is full, I've cleaned the suction strainer twice, very dirty the first time. One wheel has a slight hydraulic leak, maybe a 4 inch spot in a day of sitting. Bucket and boom work fine. Machine will creep forward if you leave hands off controls for more than 30 seconds. Has good tires, optional counterbalance weights, starts right up very good no abnormal smoke, new air filter, new starter. It's just for personal use on a small 1.8 acre lot. Not going to be using it more than a hour a week likely I only run it at 1/3 to 1/2 throttle to baby it. I'm very considerate of old machinery and definitely do not want to break anything. Not trying to be a contractor. Just occasional light use. Parking brake isn't engaging but there are some leaves and twigs around the engagement latch working to get it cleaned out. Seems very powerful, capable. Love some help with my new toy! Bryan