Skew is weak when working on greater than 10 degrees, I need to bring the boom and empty bucket right in to slew around. All other functions seem good. I am thinking of inspecting the overload valves on the hydraulic slew motor. Any suggestions for diagnosis appreciated. Slew gear oil was very low 500ml at purchase but holding well after drain and refill. Thanks. I have the ex60-5 / 75ur-3 service manual if anyone needs it. Pdf 13mb. Looking for the operators manual.
Have been advised to change all hydraulic filters. Oil looks good but machine has been idle for several years and is very likely due for a change. Will see is this makes much of a difference. I guess I should bring in as many of the rams as I can. Have a feeling that a vacuum pump on the hydraulic tank will make the job less messy. Any advice or guides will be appreciated.
Oil looks good, filters seem pristine. Sent a sample of the oil away to get tested $35 Will get a mechanic in this week if oil test comes back as ok.
Measure the pressure in the swing circuit at low idle and then again at high rpm. It's pump 3 that supply's the oil to the swing circuit. The pressure at high rpm should be 22.6 Mpa. At low idle it should be as close to 22.6 Mpa as possible. A large difference suggests leakage in the swing circuit. 4 options exist. firstly pump 3 has internal wear. Do the same test with the blade circuit, if the readings are bad in the blade circuit then it points to the pump. If the readings are ok with the blade circuit then move on to the swing motor. Oil can leak past the make up valves on the swing motor head. Remove the make up line from the motor and blank off the hose end, leave the motor end open. Drop bucket on the ground and gradually increase swing pressure both right then left. No or very little oil should be present from the open end of motor. If lots of oil is present remove make up valve poppets and inspect. Reconnect make up hose. Next remove the drain hose, blank hose off at tank. Put hose in container( 5 litre) to measure swing motor leakage. First test is stick the bucket teeth on the ground to prevent upperstructure from rotating. Rotate either left or right(doesn't matter which) and start timer. Hold swing lever at full stroke for 1 minute. Drain oil should be 1 litre or less with a maximum of 2 litres. Any more and the motor req rebuild. Do the same rotating upperstrucure at a constant speed while measuring drain. Spec is 0.3 litres with a limit of 1 litre. Again any more and motor is shot. My bet would be internal wear in the motor. Hope this helps.
Thank you very much for the detailed information. I've printed it and will pass it on to a diesel mechanic when I save some money. Thank you again.