C3 Winshield Washer Trouble

[Charles P.]

I have been trying to get my windshield washer to work on my c3.

If I prime the line with water from the reservoir cap to the pump, the pump seems to work fine-that is until it has used all the water in the line. That is it sprays water out the nozzles on both wipers, then nothing. The pump makes a knock-knock, like it is oscillating inside? when I push the wash button and sounds like it wants to work. I have replaced the gasket and the 3 little diaphragms inside the intake line . I have also checked all the rubber hoses for leaks with the old blow on the line test. Is there something else I need to do or can check? The pump/wipers have not seen much action on this car but seem willing to work. Is it always necessary to prime the lines to get these to work? Is there something inside the pump that may need tended to? (ie take the unti off the car) It seems like it is not lifting water out of the reservoir.

Thanks.

[Patrick H.]

Re: C3 Winshield Washer Trouble

Charles,

I'd say it's an 80% chance that where your intake line meets your plastic washer canister you're sucking air. This happened to me, and a touch of black weatherstrip cement cured the problem. It only takes a small amount of looseness to have it suck air instead of fluid, even though fluid may not leak from here with the "blow" test.

The other 20% chance is that you're sucking air somewhere else between the water and the pump.

Patrick

[Charles P.]

Re: C3 Winshield Washer Trouble

I suspect the air leak is somewhere in the 3 diaphragm setup that the repair kit was supposed to fix. I have tightened those 4 screws down pretty well but am afraid of damage if I overtighten. The 3 o rings around the diaphragms seem too thin to provide a seal. I am leaning toward sillicone or something like that to create a better seal. I would rather do it correctly though.

[Patrick H.]

Re: C3 Winshield Washer Trouble

Try my suggestion. What have you got to lose?

Better yet, disconnect the hose at the pump, and try and suck fluid from your washer reservoir. If you get fluid, then you know the leak is NOT before the pump connection. If you get air, I was right.

Patrick

[Gerard F.]

Also try sucking from the other end

Charles,

The reservoir end of the hose, that is, with the other end connected to the pump. You should be able to hold a vacuum on the hose (At least on a C2 washer setup, I think the C3 is similar). If it doesn't hold a vacuum then you have a leak in the hose, leak at the pump connection or a defective check valve.

Take a look at this post(sorry the picture is gone):

https://www.ncrs.org/forum/archive19.cgi?review=147800

I had a brand new check valve assembly from CC in which the three little rubber check valves wouldn't seat properly. I replaced it with one from Kragens and it worked fine.

If you force fluid or blow from the reservoir end the fluid should or air should go through the nozzles. If you suck on that end, the check valves should close and hold vacuum.

Sorry for the crude description, hope this helps. It's for a C2

Jerry Fuccillo
#42179

[Lyle24961]

Re: C3 Winshield Washer Trouble

Charles

The pump plunger may need replaced or a new O ring.
Lyle

[Gerard F.]

Here's the picture from that previous post

If that bottom check seal does not seat, and if there is a leak in the upper seals or pump assembly, the fluid will siphon or drain back to the reservoir, after every use.

Jerry Fuccillo

[Charles P.]

Re: Here's the picture from that previous post

Thanks--Patrick, Gerry, Lyle
I had the feeling that the repair kit I got from who knows catalog was crapola. Yes it resembles the original part but that is where it ends. Well not really since it is pure white and the original has mellowed to a sepia (this was kindly pointed out during Flight judging).
I was thinking to myself that a little lube on the diaphragms might make them seat better also but it could be just the quality of the part. If I understand correctly when I disconnect the hose at the reservoir I should be able to get the hose to hold a vacuum and when I disconnect the hose at the check valve I should be able to pull water easily from the reservoir which would eliminate the intake line at bottle leak theory. I will try all this evening when I get home. Does anyone elses wife love it when you pull up from work and go straight to the car? I probably will need to order a better quality kit also.

[Gerard F.]

My wife calls my C2- Gina Lollacorvette

Extreme jealousy there. If you get a new check valve assembly, check that the check seals are loose in and out and will seal properly. The one I got from Kragens works just fine although may be slightly off color.

Jerry Fuccillo

[Patrick H.]

Re: My wife calls my C2- Gina Lollacorvette

I bought the "Help!" kit at the local auto store, but used only the rubber parts. I kept the original off-white pieces. I also used some silicone based oil to lube them, and the whole thing works great.

Well, it works great now that I found the air leak at the top of the plastic reservoir connection.

Patrick

[Gerard F.]

Re: My wife calls my C2- Gina Lollacorvette

Patrick,

That's a real good idea, I'm gonna try that. My original is someplace around here. I think I lost a point or two on the pump as the judge specifically wrote down "Ivory" next to the washer pump.

Jerry Fuccillo

[Patrick H.]

Re: My wife calls my C2- Gina Lollacorvette

You can thank Jack Humphrey fior that idea.

There are a LOT of windshield washer posts in Archives from spring/early summer 2003 when I was between my Regional and National meets with the 72 and trying to fix that part.

Patrick

[Charles P.]

Re: My wife calls my C2- Gina Lollacorvette

I was going through the cars paperwork from 1981 and apparently the washer system was an issue when the car was State inspected back then also. At any rate I rummaged through my old parts boxes and was able to rescue the original part I took off months ago in my ill fated attempt to get it to work. This is the middle part that has aged like the rest of the check valve assembly. I took some white grease and rehabbed the rubber diaphragm valves on it. the only part I used from the new kit was the triple o ring. The old triple o ring was flat with age and didn't give a good seal. I now can get it to hold a vacuum when I draw on the reservoir end of the tubing and I can blow going into the pump I think. (It is taking alot of pressure to blow through though--is that normal??) It is late now so I will have to wait for the ultimate test with H2O tomorrow. The Corvette ROARING to life would ruin the kharma of the neighborhood at this hour. Remember this apparently has not worked since at least 1981!
Restorers note: I noticed that all 3 of the diaphragm rubber umbrella valves on the original have a different numbers on them (100, 55, 45) as if they have different resistances to pressure or some such. Strange.