Headlight Squirter Anti-drip Valve

[Duane D.]

My 5-port windshield washer pump (new) on my 1970 Corvette will not hold "prime" and did not function properly during a recent NCRS judging event in Sevierville, TN. When I contacted the seller,Corvette Central, I was told to check the referenced valve for possible leakage. Where is this valve located and what is its function? Another question, are the bottom two outlets of the washer pump for the headlights or is it the top two outlets?
Duane Dunlap

[Terry M.]

Re: Headlight Squirter Anti-drip Valve

My 5-port windshield washer pump (new) on my 1970 Corvette will not hold "prime" and did not function properly during a recent NCRS judging event in Sevierville, TN. When I contacted the seller,Corvette Central, I was told to check the referenced valve for possible leakage. Where is this valve located and what is its function? Another question, are the bottom two outlets of the washer pump for the headlights or is it the top two outlets?
Duane Dunlap

Duane Contrary to what you have been told, the anti-drip check valves have nothing to do with the windshield washer pump prime.

The check valves are right behind the headlamps. They split the single water line into two lines that go to the headlamp washers. They function as both a check valve and a "T". Their purpose is to keep the liquid in the line that goes to the headlamps and keep that water from leaking onto the ground when the headlamps are lowered.

Any air leak into the suction line will cause it to lose prime and fail to function. Check the suction side umbrella valve in the plate at the washer pump. You might try applying a small amount of silicone grease to all the umbrella valves while you have the plate out. Check the hose to the washer fluid reservoir. The end connections must be tight and the hose must have no leaks.

There ought to be somethign in the AIM about where to connect which hoses, but from a functional standpoint -- it doesn't matter.

[Robert S.]

Re: Headlight Squirter Anti-drip Valve

The 1970 AIM shows the headlight washer hoses attaching to the lower 2 pump outlet ports.

[Terry M.]

Re: Headlight Squirter Anti-drip Valve

My 5-port windshield washer pump (new) on my 1970 Corvette will not hold "prime" and did not function properly during a recent NCRS judging event in Sevierville, TN. When I contacted the seller,Corvette Central, I was told to check the referenced valve for possible leakage. Where is this valve located and what is its function? Another question, are the bottom two outlets of the washer pump for the headlights or is it the top two outlets?
Duane Dunlap

After thinking about the washer system some more I have to amend my earlier answer. It is possible that malfunctioning or missing headlamp anti-drip check valves could allow gravity to suck all the fluid not only from the lines to the headlamp washers, but also from the pump itself, and I suppose all the way from the reservoir. That would ultimately drain the reservoir entirely, however, and at that point the prime to the pump would be the least of your issues.

I would devote my time to the integrity of the supply line to the pump from the reservoir, and then if necessary deal with the puddle under the headlamps.

[Pat M.]

Re: Headlight Squirter Anti-drip Valve

Both of your replies are right-on, Terry, and that's why you must have firm umbrella valves (including the outgoing valves to the headlamps) AND good check valves to get a really good seal.

[Terry M.]

Re: Headlight Squirter Anti-drip Valve

Both of your replies are right-on, Terry, and that's why you must have firm umbrella valves (including the outgoing valves to the headlamps) AND good check valves to get a really good seal.

When I first posted I thought the umbrella valves would stop the syphon to the headlamp washers, but as I thought about it more during the day I realized weak umbrella valves would let all the fluid flow through.

Crazy that I go about my daily business thinking of these postings. Must be something wrong there.

[Pat M.]

Re: Headlight Squirter Anti-drip Valve

Crazy that I go about my daily business thinking of these postings. Must be something wrong there.

At least I know it's not just me. Think it might affect anyone else on this board?

[Terry M.]

Re: Headlight Squirter Anti-drip Valve

Nah, it's just you and I.

Maybe some retired folks might fit that catagory, but you wouldn't think it would be an airline pilot or an MD, even an MD from MD. I bet you and I could generate the same list without a lot of trouble.

[Duane D.]

Re: Headlight Squirter Anti-drip Valve

Thanks to everyone that replied to my thread, I have a much better understanding of the problem. After reading your comments, I cut off a short piece of rubber hose at each fitting location getting a much tighter seal. The washer pump now appears to be self priming. I get fluid at the four locations; however, it takes 7 or 8 sweaps of the wipers before the fluid arrives. It's not perfect, but better. Thanks.