C3 wiper moter pump

[Jeff W.]

Is the washer pump that has the 2 plastici nserts on the right hand side of the backing plate a replacement or is it original? The one on my car now does not have any holes on the right side of the plate.
Thanks for the help.

[Chuck S.]

Re: C3 wiper moter pump

Is the washer pump that has the 2 plastici nserts on the right hand side of the backing plate a replacement or is it original? The one on my car now does not have any holes on the right side of the plate.
Thanks for the help.

Probably. I have no idea what you're describing without a photo, but many of the plastic parts on your "original" pump can be removed and reused on the replacement wiper motor if the new plastic parts are incorrect. You may have some minor challenge in figuring out how to clean them up and polish them to look as new as the wiper motor.

[Dick W.]

Re: C3 wiper moter pump

Also need to know what year C-3 as there were more than one style used.

[Jeff W.]

Re: C3 wiper moter pump

The pump on the left is the one that came off of my 1972 (the plastic pump was cracked and could not be saved) the one on the right I just got in the mail. You can see the difference on the metal plate on the right of both units. Mine did not have the 2 plastic inserts.
I think I attached the photo, if it worked it will be the first time in 2 years.
Thanks for the help

[Alan S.]

Re: C3 wiper moter pump

Jeff,
I just looked at my 71, known original, and no plastic inserts. (It is a 5-port). I looked at the picture of the pump in the GM Shop Manual, and no plastic inserts. The picture is credited to Chevrolet but who knows when it was taken? So my answer is "I'm no help".
Regards,
Alan

[Terry M.]

Re: C3 wiper moter pump

I've got a 5-port pump, so I'm no help.

[Jeff W.]

Re: C3 wiper moter pump

Isn't there a bracket that goes into those plugs for the headlight spray? I don't know if they used 2 different back plates or if they changed for 1972 because that wasn't offered.

[Dick W.]

Re: C3 wiper moter pump

Just looked at our '72 which we have had for about 25 years, no plastic buttons

[Chuck S.]

Re: C3 wiper moter pump

The pump on the left is the one that came off of my 1972 (the plastic pump was cracked and could not be saved) the one on the right I just got in the mail. You can see the difference on the metal plate on the right of both units. Mine did not have the 2 plastic inserts.
I think I attached the photo, if it worked it will be the first time in 2 years.
Thanks for the help

I will probably be little help as well, but maybe I can give you some things to think about.

As far as I can tell...both pumps are three port pumps, the one that came off the your car HAS NO holes/filler plugs, the one you received in the mail HAS two holes/filler plugs. Its a hip shoot for me, but it's unlikely the one you received in the mail is typical of 72 Corvette washer pumps. This assumption is based on your pump being original (wiper motors are not a high maintenance item), and the fact that I have not seen the plastic filler plugs at that location before on C3 wiper motor/pumps.

If my thinking above is verified with further research, you are faced with trying to combine the two pumps/backing plates into one working pump in the original configuration, or looking for another original in good condition. Combining the two pumps may not be possible; some of the fabrication methods used on such expendable, non-repairable components are not hobbyist friendly. I haven't tried to visualize the installation, but if the plastic filler plugs are not visible during judging (unlikely), it's a non-issue.

[Jeff W.]

Re: C3 wiper moter pump

Thanks Dick and everyone

[Joe L.]

Re: C3 wiper moter pump

Jeff-----


I expect that the "plastic inserts" are actually plugs used to cover the holes used to mount the 1969-only solenoid valve. I have no doubt that the plugs were originally installed at the factory, though. It may be that for sometime after 1969 the backing plates were manufactured with the holes and they were plugged for applications not requiring them. Whether this was done for PRODUCTION pumps, SERVICE pumps, or both, I do not know. However, my expectation is that it was done for both for some period of time.

In any event, if you wish to use your original backing plate, you should be able to transfer the piston and cylinder unit from the pump you just purchased to your original pump. All of the parts should be interchangeable.