I am about to install a Trico vacuum type windshield washer in my 50. I have come into an original NOS chevy accessory kit that contains all the nozzles, tubing, fittings, instructions, etc., however the dash mounted control knob with the center button that activates the washer was not included. I found a used one on e-bay (Part Number 81174-16) and got it in the mail today. I am not sure if this control is complete or is perhaps broken. The small button that is supposed to activate the washer does not seem to be connected to anything. I can see the brass shaft of the control is hollow, and I suspect there should be a small shaft and perhaps a spring which may depress a vacuum valve on the innards of the control? Before I begin taking the control apart, I would appreciate some advice on wether or not this unit is complete, broken or what might be missing. Any advice would be welcome.
Last edited by Midi; 12/03/2311:01 AM. Reason: add part number
My best guess is that “button” is actually connected to a piston or plunger in the body of the control. The washer fluid inlet and outlet hoses connect to the brass nipples.
If I am correct I expect that the plunger/piston is stuck in the down position. The seals have probably hardened with age. The return spring is not able to push the plunger back to the home position.
I would consider soaking the control portion of the assembly in automatic transmission stop leak. That might soften the seals.
Not sure on a 50 but does the washer jar have vacuum hose fitting on top of it? If so it may be like my 47 and the switch would control the vacuum to it, vacuum raises the plunger and when you let off the button a spring pushes it down to force the washer fluid out. A good test for your switch would be to see if it holds vacuum on one side and releases it when the button is pushed in. The picture looks like the button is stuck in, May just need a little lube. Hope this helps, Denny
Dens Chevys 1927 Speedster 1928 coupe 1941street rod 1947Fleetline 4 door 1949 1/2 ton Pickup (sold) 1954 210 4 door 1972 Monte Carlo 2003 Corvette convt..
The windshield washer control problem has been discovered from a diagram found in a 1950 Chevy accessories installation manual given to me by my neighbor. (See the attached diagram). It would seem my newly purchased wiper/washer control knob is missing a few parts. There should be a pushrod and a spring that connects the washer button to the vacuum control valve within the controller. These parts would be held in place by the knob which has a set-screw holding the knob to the shaft. I would think that they would be easily lost when the device was removed from the donner vehicle. I'm back to looking for another washer/wiper controller. Thanks for those who have responded.
