The connecting rod “connects” the crankshaft to the piston, to create a “stroke”, creating compression (in an air compressor) or combustion (in an engine). When a pump is run low on oil the conrod(s) will usually freeze onto the crankshaft journal, seizing the pump. At this point you must replace the conrods. Be sure to torque the conrod bolt down to the specified torque setting per the manufacturer.
15-pc Thunderbolt Black Oxide Drill Bit Set
1/4" x 50 Ft Noodle Air Hose with Coupler and Plug