Trying to wrap my head around the PET illustrations for the windshield washer pump.. There is an illustration for an electric pump which is what I'll be using, however it seems to only call for "T" pieces - but I believe that's being shown with the early chrome nozzles.

Did maybe early nozzles incorporate a check valve, but the later black one didn't?

The illustration for the later black nozzles lists a "T" shaped "valve with valve" (probably a separate check valve, no?).

Anyone know what's what here?


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I like a check valve in that system.

I'd add one if it didn't have it.

I'd also run that stuff on the bench before I installed it in the car.

I've used welding torch tip cleaners to clean/modify the spray nozzles many a time.

Some of the real late German nozzles have neat "patterns" and many are heated nowadays. I'm watching for something modern to replace the original stuff.

The black nozzles I have are new and unused, so I'm gonna use them for the time being.

I just realized that the model number for the early nozzles (chrome) are described in the first PET illustration as as "Spray Nozzle" and the same model number in the second illustration is described as "Spray Nozzle with Valve" ... the later nozzles are just described as "Nozzle Black" - so it's a pretty good indication that separate check valves were used with the late black nozzle set up.

If you're using a normal bottle from a /4 you will need to add some sort of air-inlet/valve to the cap as the /4 cap valve is meant to keep the spare tire pressure above a certain level.
A stock /4 bottle has no way to let air in if you convert to an electrical pump setup and your pump will burn up trying to suck against a vacuum.

I did the cheap and quick hack for my setup, which is to simply drill a small hole in the cap.
http://www.914world.com/specs/tech_el_washer.php

Me too.

Yeah I had it in the back of my mind that I'd need to drill a hose in that cap at some point. Any interesting alternatives to a simple hole in the cap?

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From experience, the early nozzles require the check valves. I fitted an electric pump when I did my -6 conversion, and on one of the first "spirited" test drives was shocked to see clear liquid splashing on the screen! At least I knew it wasn't coolant.... ;-)

Think I looked at the PET for a 911 and found the check valve part numbers - this fixed it.

- Tony

When I bought the car 8 years ago, ( ‘75 2.0) the seller installed an electric pump. It works just fine ( I only use it if I have to go to the MOT every 2years) but in between the nozzles leak water regularly. If I don’t wipe it off instantly , it creates stains that are very difficult to remove. And I have no idea what is causing this.

Sounds like you need the check valves (item 10)...?

Click to view attachment

- Tony

Thx Tony, as far as I can remember ,I don’t have any check valves, but I can’t check it now because I’m in Spain right now, the weather here is a lot better than in Belgium. I’already thought that it would be something like that but I didn’t know where they were supposed to be. After 8 years, I’m still learning!

Check valves are one-way valves. Are these really pop-off valves instead? Pop-off would allow spray but not weeping/leaking. I just did my electric pump install but did not include any valves, maybe I need to reconsider. I’m curious why 2 valves instead of 1 valve before they branch to the 2 nozzles.

Pump may have check valve built into it.

One will work fine. Might allow one nozzle to take longer to spray but two are not a requirement.

Not pop off valves that require a certain pressure before they release, at least none of the ones I've seen are.

Too much CIS injection in your past...

The early nozzles have 1 check valve each, but the later models (black nozzles) use a “T” fitting that has a single check valve

Is this what you need?
https://914rubber.com/check-valve-w-s-washer-l-shape

That's what I ordered, but PET (914 specific) only shows a valve that's "T" shaped (I know you have those too), no single valves that I saw.. I already had non-valved "T" piece so I figured the two individuals would be fine. And as pointed out, that's how 911's were done.

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