Basically, you fill your crankcase like normal, then add oil to the accumulator per manufacturers spec. Usually 2-3 quarts. Install cap and air it up with shop air to the pressure your engine runs at idle hot. From there it's automatic. It'll dump if the pressure falls below that point & refill when it's higher.....most have a solenoid and switch so you can turn it off or use it to prime the engine on cold start.