adambowers123
Member
We have a Hyundai 160 -9a that is in our fleet. We are primarily a trucking company and my mechanics are diesel engine technicians. This unit has been giving us fits for the past 6 months. When at operating temp, the joysticks will start to jerk and shake uncontrollably to the point of having to turn off the hydraulics and let it settle, and restarting. This does not happen when cold. It primarily happens in swing function, but can happen in any motion. My guys have looked and tracked, to no avail. We called our local Hyundai dealer, he put gauges on the pump, said it was weak, and needed replacement. We ordered a aftermarket pump, drained and flushed system, replaced and no difference. We called back and that dealer has given up the dealership. Next, we called the new dealer, had a tech come out, and he said it is the swing motor. I hate to keep pulling at straws, and throwing parts at this unit, but it is out of our typical scope and even the local dealerships are having trouble diagnosing.