Re: Magnumatic washer pump and heater valve

Posted by Jim McDermaid On 2014/11/17 19:03:27

I restored my MagNuMaticHydrostatic pump which looks just like the pictures on this thread.

1954 Cavalier

So here is what I know.

The McVee kit appears to be the only source for the parts that I could find. It had all the rubber parts. The two old seals on the pump plunger were my biggest problem as the rubber was petrified.

The new seals work perfect. Be careful when you remove the old rubber seals.

The pump body is Bakelite which is brittle so handle it carefully.

The rubber valves in my pump, and the Co-Ordinator valve worked so I didn't drill out or remove those parts. The cardboard gasket in the lid seems to be OK in my pump so I left it alone.

If I had been more careful I could have saved the little disk valve on the bottom under the solenoid but the replacement works fine.

Understanding how the pump works in action helped me understand this thing better.

So here goes . . . . You momentarily push the button in the center of the wiper control knob. This activates the solenoid which opens a valve to admit vacuum into the pump.

Vacuum in the pump chamber holds the solenoid valve open until the small spring on the plunger resets the valve cutting off the vacuum. This is when the piston hits the top of the stroke.

The big spring inside the plunger causes the plunger to return to the bottom and pump the water that was pulled into the pump chamber to the nozzles through the coordinator valve. The hose from the bottom of the pump is the pump discharge. This water flow moves the coordinator valve which admits vacuum into the coordinator cylinder which starts the wiper motor.

So a single brief push of the button sprays a good amount of water on the windshield and operates the wipers long enough to clean the windshield without turning the knob.

My car had the complete pump under the hood (for show) and remnants of the rubber tubing under the dash.

The instruction on this Forum was of great aid in the restoration of my pump. I use the washer all the time and in fact plan to dry it out before the temperature in Phoenix AZ gets close to freezing, noting Nobody sells washer fluid that won't freeze in Phoenix.

I assume the glass jar I have and the pump was original to the car. I had to get the proper wiper motor from WiperMan and found a workable coordinator on eBay. There is a decal on the pump lid which I believe is available reproduction. As I recall the red solenoid is 12 volt and the brown/black is 6 volt.

Jim