Hi, I'm asking this question on behalf of my father who isn't the most computer literate guy around, he's an opal miner and owns a Hitachi UH083, its old and breaks all the time but he continues to fix and keep digging away. Recently we were out in the field and machine was working fine, it then started leaking a lot of hydraulic oil out of the turn table and it wasn't turning right at a good speed. The old man has since taken out the swing motor and replaced a bunch of seals and bearings at the bottom and the leak has now stopped, however the slow turning right is still happening. it turns left with no problems. Does anyone have any advice on what would cause this problem of the motor not turning right at the correct speed and the best and cheapest fix?
Not entirely sure on that model, but look at the swing motor head, there should be two cartridge valves which are reliefs. If they haven't been inspected, remove them keeping track of which one came from which hole, check the O-rings and backups on them, could be a blown out O-ring, if that all looks okay, switch positions with them, see if the problem changes over to the left direction.
If it was leaking oil out of the swing bearing i'd be more inclined to think it is a problem with the turning joint seals. That could cause a loss of travel pressure. If i was you i'd be doing pressure tests of both tracks both forward and reverse.