I have a polaris 360 that has been working fine for 5 years. It started getting stuck in the same corner and would not back out. I have completely rebuilt the unit, replaced the back up valve and the same problem is happening. The swivels appear to be fine and there is no leaks in the hose. I am going absolutely crazy trying to figure this out. I have cleaned all filters and clean the hose filter often. Wheel RPM is 28. Any help would be appreciated. Thank you