Windshield washer pump

[psoucy]

I know the windshield washer pump is driven by the wiper motor, is there a solenoid that opens when you push the wiper knob to call for washer fluid. Just want to know how it works.

[RustyPile]

I guess one could call it a solenoid. On the back side of the shaft that drives the arm for the wiper linkage is a 4 lobe "cam". There is a cam follower attached to the linkage for the piston of the washer pump. In the "resting position", this linkage sits off to one side a bit. When the "solenoid" is activated, this linkage is pulled into alignment and the pumps starts pumping.

I don't like this arrangement because the wiper motor is mounted inside the cab, and the pump is mounted to the motor. This means that water is brought into the cab. If a leak develops, water is dripping inside the cab.. I installed a reservoir with a built-in pump in the engine compartment. I disconnected the factory plug on the old pump and fabricated a harness and plugged this into the new pump. Now, the pump and associated hoses are all in the engine compartment.

[HO455]

The wiper motor moves a rubber diaphragm that pulls water from the tank and then pushes it out through the hose to the windshield. There is a solenoid that engages the wipe motor to the pump. This video should help explain what I'm trying to convey.

https://youtu.be/nUax433B3Bw

If your having problems with yours and you have a 67 there may not be any parts for the pump available. Several years ago mine failed and I either had to change to a later year wiper motor or convert to a different style pump due to no replacement diaphragms. I went with a late 80's Camaro pump mounted that I mounted on the tank in under the hood.

[psoucy]

So when I turn the wipers on should the pump also be pumping or should the pump only come on when I push the button for washer fluid because that’s what’s happening right now. If the wiper motor is turning the pump is pumping.

[Ironangel]

The washer pump is driven by a 4 lobe cam adjacent to the wiper motor. The washer assembly can be removed from the wiper motor by removing two screws, one on each end. I'll be honest with you and say that rebuilding the existing pump can be sketchy at best. It's a bogus design that can flood the inside of the dash with washer fluid and will soon fail again if you do get it right, poor design! You have three options, rebuild the one you have, (which seldom lasts or even works) Replace the whole washer pump with a new unit, (I think this is the way to go) https://www.classicparts.com/1964-72...ctinfo/67-825/ Or forgo any washer fluid inside the dash and go with this, https://www.classicparts.com/1955-87...ctinfo/67-821/ This unit can be located under the hood near your washer fluid container, simply extend the switch wiring.

[Ironangel]

Originally Posted by psoucy

So when I turn the wipers on should the pump also be pumping or should the pump only come on when I push the button for washer fluid because that’s what’s happening right now. If the wiper motor is turning the pump is pumping.

Good question! I've never had one work long enough to be able to tell. I believe the washer should only work when the knob is pressed, not turned...

[HO455]

Before pulling the pump. If the washer pump is working all the time it may be the switch. The switch controls the pump by pushing in on the switch while turning the knob. Over the years they get worn and loose so you may be able to push the switch in without turning it.

The washer power connector is the 2 wire one circled. (Thanks to LockDoc for the picture. ) 12v positive comes in on the yellow wire and the blue wire is the negative side of the power.

The switch controls the negative side not the positive side. For a quick test pull the plug off and test the wiper. If the pump still works the problem is in the pump. If not then your switch needs to be checked out.

[psoucy]

Thanks for the help.

[HO455]

You're welcome and good luck with the troubleshooting. Let us know what you find.