Re: Mag Nu Matic Washers

Posted by BH On 2008/3/24 11:59:56

The first place I saw the washer system called that was in the Accessories section of the factory shop manual. Yet, it wasn't until some ten years later, when I disassembled a rusty old pump & cover from a parts car to repair the one on my first Patrician (which had half of its innards missing), that I understood the function behind the name.

Though I was expecting some sort of little motor, it is a little electric solenoid that merely opens a vacuum passage. The resulting pressure differential retracts a spring-loaded plunger inside the jar to load a plastic chamber with washer fluid - much like a syringe. When the vacuum source is cut-off, the return spring pushes the plunger down, and fluid is forced out the washer nozzles.

However, I've never been quite sure about the function of the other plastic "block" on the jar cover. Upon finding some little rubber flaps (valves?) inside one that I disassembled, I was reminded of repair kits for 60s/70s-era Trico pumps on full-size GM cars that dispensed the washer fluid in a pulsed stream, but I've only seen a steady stream from the two systems that I've had working on Packard V8s.