I have a Komatsu WB146 backhoe and have replaced the main valve body behind the seat.. When putting out riggers down, turning hard to left or right or using either bucket, when you start loading the hydraulics up the machine cuts off. This is the 2nd main valve body I have put on within a week and it continues to do the same. I thought maybe I would try and use it and maybe if a valve was sticking it would work itself out but that is not happening. Any help would be appreciated.
Do you know if the pressure is set correctly? Are you using the same relief valve with the new valve body? Post your serial number with the model number and someone with more knowledge on Komatsu can help you further.
Is your fuel system in good working condition? It could be as simple as clogged filters or poor fuel delivery due to old lines.
Do you have gauges? We can help but you gotta have the basics
BigWrench55, Thank you for responding. I have checked the fuel lines and put new filters on it. I did not change the relief valve when I installed the new valve body, do you think that's the problem?
There will be engine performance testing that should be done to eliminate that the engine isn't the problem. What is the rpm at idle? What is the rpm at wide open throttle? What are the rpm when putting a load on the engine idle and wide open throttle? Then you will need the proper gauges to test your hydraulic pressure. Again model and serial number will get this ball rolling faster. I know nothing of your machine, but if I were called out to find the problem. Those are the things I would check.
What was the reason to replace the valve body in the 1st place? It sounds like a relief valve problem.
did you find the issue to this?