hello, I have a hitachi ex50urg mfg number 10e-0454. I recently bought this after the previous owner had a center joint failure. Everything functioned up until a major hyd. leak from center joint. The previous owner bought a seal kit and replaced the seals and re installed the center joint. The external leak is resolved however now the right track no longer does anything as well as the bucket curl, all other functions seem to be normal. he didn't want to spend any more time and money on this so now I get to try. I have changed the oil and replaced all the filter and cleaned the tank screen, no change. I could feel two of the hoses on top of the center joint move when left track lever was applied, absolutely no movement on other two hoses when right track was engaged, no sound of hydraulics or motor noise what so ever. So I am thinking that the center joint might be bypassing internally now. I disconnected the lines going to the final drive for the right track and engaged the lever and had flow but no pressure. I am working on getting a gauge to test before the center joint. I am concerned that debris from center joint failure is in a valve due to bucket curl and one track not working. I don't know if a bypass in the center joint would affect the bucket curl in any way, or if I have 2 separate issues at the same time. I would love some thoughts on what to test next. Thanks
Good morning, I am having the exact same issue with my machine. The right track quit working and the bucket cylinder quit working. The bucket cylinder will move but extremely slowly so I’m guessing there is flow there but no pressure. Did you end up figuring out the problem?
Good day Sounds strange, could it be a crossed line, see attached may help. Kind regards Uffex
I don’t think it’s a crossed line. The machine has been used once or twice a year over the past ten years and has worked fine besides the odd hydraulic leak.I hauled it 3hrs home, unloaded it and drove it for maybe 5 min and then the right track quit working and bucket cylinder quit. The cylinders do leak pretty bad, is there a chance that the hydraulic system got air locked?
Good day i would suggest if the case was an air lock it may effect more than one track, I will dig out my stuff on the machine and see if there is a logical explanation. Kind regards Uffex
Good day IE I am short of the correct hydraulic schematic for your machine. If you have one please post and I will see if I can help out some more. I suggest starting with checking the pilot pressures at the spool slice for those functions that are not responding. Kind regards Uffex
Do you still have this machine, would you sell the swing motor off of it?
I had my center joint rebuilt and put it back in myself. On the top side I mixed a couple of hoses and one of the tracks didn’t work. There are a couple of connections that are so close and easy thread onto the wrong fitting. Could be your problem perhaps. I don’t think that center joint has anything to do with bucket curl. Tracks and forward blade are controlled by center joint. I not sure if it connects to swing motor as well.
There is a small pilot filter buried behind the pump. I had to take off the lower plate to change it.