Anyone who has built or rebuilt an engine knows — or should know — that one of the final steps before the first start-up of the new mill is to prime the oiling system. Traditionally, that is done by chucking up an oil pump priming tool into a cordless drill and running the oil pump for a few minutes until you have oil throughout the engine, and pressure at the gauge.
However, with the explosion in popularity of gerotor pumps, using a mechanical pump priming tool isn’t an option. That leaves you with only one way to properly prime the oil system: via pressure. Not a new concept by any means, the Melling MPL-201 pressure priming tool makes the job a snap.
A larger, more robust version of Melling’s MPL-101 one-gallon pressure priming tool, the external difference is immediately obvious, with the previous -101 looking like a small propane tank, While the new -201 looks like a mini pony keg, both due to its shape and its stainless steel construction.
Functionally, the -201 has a number of improvements, starting with the increased-capacity tank made from better materials. A large tank opening houses a revised pressure valve, which incorporates a standard Schrader valve to pressurize the tank with any air compressor and a 75psi blow-off valve to prevent overpressurization of the vessel.
Additionally, the MPL-201 comes with an eight-foot long chemical-resistant hose with swivel fittings at each end, as well as three common adapter fittings — including a 16mm LS adapter. These parts are critical to properly connect the pressure tank to the engine block. The flow of pressurized oil is controlled by a quarter-turn valve for easy control of the oil flow (which is very handy if you’ve forgotten to put the oil filter on… or so we’ve heard).