Cavu2u

OK. What's the secret of aligning the washer pump's oblong drive cam hole with the Wiper Motor's drive stud? I believe it can only be done in the wiper motor and pump's PARK position.
I'm attempting to engage the washer cam to the wiper motor's drive stud by aligning the washer cam hole's open end onto the stud. But when I do and the washer's mounting flange feels even and snug to the motor, the three attaching screw holes don't align with the motor's holes. Perhaps I need to twist the pump with a little force in an effort to align the mounting holes, but had better ask first.
Any suggestions are most welcome.

Steve

Also, the wiper action goes to and stops in the approximate PARK position when the wiper selector button is pushed (pump activated). This can't be normal washer operation, as it takes rotation to drive the pump. Correct?

Mooser

If I get what you mean...
The 4 star cam in the pump is "spring loaded" by the rest of the pump mechanism and that might be what you are feeling when you are trying to install it. In theory, that pin comes out of the pocket on the star cam and travels around the 4 lobes so lining it up shouldn't actually matter (I have no proof but that's how it works so how can it not find it's way back in)
Anyway, turn the pump to align the screws and you should just see the pump plunger get compressed a little when you do it
M

theandies

I'm about to ditch that old mechanical pump and go electric. I'm buying a 1975 pump and going to mount it on my 1971 washer jar then cover the wiper motor with a '75 cover. I think my old pump is what's causing my wiper to stop working sometimes as I've notice it would squirt even when I wasn't pressing the button. I think the pump has a mind of it's own and is locking up the system intermittently. The conversion will be less than $50.

Mooser

Hmmmm, sounds familiar
https://www.corvetteforum.com/forums...post1597666362
LOL
M

Cavu2u

Thanks for the comeback sir!
I was with the understanding that the "stud" on the rotating wiper motor engages the pump's cam in it's oblong "hole" and rotates the cam, and the lobes of the cam push the actuating lever of the pump, making it, in rather accurate terms, suck and blow.
I'm guessing this now, that the reason for the oblong hole in the cam is to engage/disengage (turn ON/OFF) the pump.
The pump's cam has to rotate, in order for the pump's actuating lever to "pump". No?

I always appreciate your input Mooser. You've helped me out many times.
Steve

Cavu2u

I hear ya, but just haven't brought myself to go that far.
Yet.

Honestly, it doesn't rain that much here, and it's a very rare occasion when needed. I'm just a guy who likes things as they were from the factory.

Steve

Cavu2u

He ought to make a few and offer them up for sale. They look as functional as they are beautiful.

Steve

Mooser

No your understanding is correct but that pin that follows the outside of the 4 star cam and runs into the plunger pump is the bit that I think is pushing back against you when you are trying to put the motor pin into that slot. I still believe that it is supposed to "find" that slot on it's own but I had to line it up on mine as it just didn't want to turn and go in on it's own like I think it should have.
M

Cavu2u

Thanks Moose.
In that case, I'll disassemble the washer pump (the 4-screw nozzle cap), which removes the force to that pump cam follower caused by the pump's internal spring. Next I'll mount the Washer Pump on the Wiper Motor with the 3 screws, THEN install the pump's spring, piston, and nozzle cap.
Wish me luck.

Steve

Mooser

Should work if you can't "twist" it so the pin goes into the slot.
I can't test mine anymore but I would still have though the pin would locate it on it's own but maybe it never really comes all the way out when the motor parks and stays within the slot and that's why we need to put it together in place. Maybe I'll have to dig out an old one someday and check that
M

Cavu2u

No, don't bother M. I've given up on it now, for I've fitted the pump on the motor 3 times now with the same result. It's just not going to work as it is now. I've already spent too much time on it, and your kind help was very good of you. Not many of my rebuilding/repairing chores have gone beyond repair. AAMOF, this is the only one that comes to mine. I purchased a new pump on fleabay that was advertised for a '73, but it was different in the mounting plate and terminal design. It did fit on the motor, but operated the same unsatisfactory way as the original. There are other things I need to "attack".

Defeated but grateful,
Steve

theandies

If only I had a CNC machine.