The question usually applies to the following Malabar mobile axle jack models: 50P9AR, 50P9, 60P9, 60P10, 65P10, 65P9AR and 65P10AR. All Malabar jacks are shipped without hydraulic fluid in the jack reservoir. After filling the reservoir it is necessary to prime the air operated pump at the “bleed” fitting. Refer to the jack Owner’s Manual for complete instructions for this procedure. Note: The secret to priming the pump is to slowly operate the pump by only partially opening the air valve.