Troubleshooting Hydraulic Steering system

Oct 1, 2019
2
MacGregor 26x Lac Gagnon, PQ
I'm the 2nd owner of an 03 mac 26x with upgraded admiral series hydraulic steering system. The system gave out , oil was a bit low, no leaks found , nothing else found, refilled but still not working. Anyone has experience how to bleed this type of system. Many thanks!