1978 Case 850B

Ok have a case 850b that turns right great but when you try to turn left you can feel it grab and then let go and won't turn. We tighened the left track where it matched the right and actually got it to turn once for a second and then back to some thing, left master cylinder was empty and we put some in but haven't bleed it yet due to line being a pain. We also learned that trans is low on fluid and haven't got it topped off yet. I've talked to Case and one told me that the left brake is what wrong but I didn't think the levers controlled the brakes and the second dealer told me I needed to pay $10,000 to $12,000 to rebuild the left cluthes. Somebody please give me some ideas, we just bought this machine and it was sitting in a bad spot to try it but I did I just seen that both ways was going to catch, MY MISTAKE THERE.