The pressure fill unit has a Schrader valve that allows you to pressurize the tank to your desired pressure as indicated on the gauge. It has a pressure relief vent to prevent over filling and to allow you to relieve all pressure in the tank when you are finished.
You must install a pre-filled oil filter with oil before you introduce oil into the engine. Summit recommends filling the tank with 3-4 quarts of oil and sealing the filler cap tightly to hold pressure. Confirm that the oil filler valve is closed (horizontal position). They recommend pressuring the tank to 100 psi after you have pre-warmed the oil in the sun.
Attach the priming hose to the tank fill valve and the other end to the engine adapter fitting installed in the engine's oil pressure gauge fitting . Late model Hemi engines use a 1/8-27 NPT fitting, Ford modular engines, take a 1/4-18 NPT or M12x1.50 and GM LS engines take a M16x1.5 fitting. The supplied filler line is six feet long with a -4x1/8_NPT ball valve fitting.
Confirm that the fittings are tight and slowly rotate the ball valve filller (to vertical position) to allow oil to flow into the engine. A BEST PRACTICE is to slowly rotate the engine by hand for several revolutions to ensure that oil makes it to all the bearings. Remember that it has to flow through all the flow passages including the transfer passages in the crankshaft, the lifters and pushrods and any passages that feed them. Keep the pressure on until you observe oil flow out of all the rocker arms. This ensures that the rest of the engine and the valvetrain are well primed.
Leave the fill valve open at this point to dissipate all the pressure in the tank. When the pressure gauge indicates zero pressure, close the ball valve, remove the feed line to the engine and plug the opening or reinstall the oil pressure sending unit. Your engine is now prelubed.