W116 Headlight washers

[Oversize]

I've been trying to make sense of the system and it totally baffles me. The windscreen washers work, but no headlight washers. Help!



To me there seems to be two pickups out of the bottle, one for each pump. There's a pump for the windscreen and one for the headlights. Note that it's common for the pickup connectors to break off the underside of the lid, hence a previous repair.



The windscreen washer hoses go straight from the pump to the screen jets. But the headlight ones are different. Note a hose has been removed from the check valve:



Here's the pumps hidden behind the LH headlight:



The headlight pump's right under the headlight and very hard to access:



So what's the go here?? It looks like the headlight hose goes back to the washer bottle into a T piece. Maybe excess pressure is returned into the bottle? Somehow there's supposed to be enough pressure left to cross the open section of the T piece, into another hose and off to the headlights via the check valve. I'd suggest the T piece is also there to stop syphoning of the bottle, as the headlight jets are the lowest point in the system:

 

[Michel]

Nice close-up photography

 

[Styria]

Hi Mark, I must admit to getting a quiet chuckle out of Michel's reply. I am quite sure that he knows as well as I do, that he got lost by the time he got halfway through your pics. and your post. Now, to the problem at hand - honestly, it requires some serious thinking and re-thinking of what I know, and what I don't know - very little of the former, and a lot of the later.To be honest, in the sixteen or so years I have owned Gleaming Beauty, my washer system has never worked, and I have never really bothered to work out why, or that I should connect the system.

I have removed the two washer motors for servicing, and cleaned up that area very carefully, and I have tested them on the bench to be working perfectly. However, I have replaced the standard 6.9 washer bottle which used to sell for $600.00 odd dollars when they were procurable new, and have replaced it with a specially manufactured Alloy unit and I have never bothered to connect up the system to the Alloy unit. I will one of these days. Unfortunately, right at this very moment, I am unable to clarify for you how the plastic distribution system incorporated in the top of the washer bottle works. It will require some serious thinking. Regards Styria

N.B. Come to think of it, this could be one for our doctor Bill (WGB) in West Oz. Wonder what he knows ! (Just a thought).

 

[Michel]

Hi Mark, I must admit to getting a quiet chuckle out of Michel's reply. I am quite sure that he knows as well as I do, that he got lost by the time he got halfway through your pics. and your post. Regards Styria

Spot On Godfather

 

[Oversize]

Sorry guys if I've added to the confusion.... I'll have to check if the headlight washer pump works and if not, the wiring. I know the headlight wipers work and assume the pump runs off the same switch? I'll take a guess that the open T piece simply acts like another jet (but squirting into the bottle) to bleed excess pressure. I'd say both pumps are exactly the same (with the same output) and what's ok for the windscreen jets, might be too much for the headlights. But I must say that the open T piece looks far bigger than any washer jet and I'd have thought it'd bleed off almost all the pressure from the pump....

 

[Styria]

....please explain ? No, no, just kidding. I think, Mark, that you must be the only one that's managed to get the headlight wipers to work. It is my understanding that the headlights must be "ON", and you push the washer/wipe button and "Hey Presto", the wipers should work. Is that how you carried out the test, and do you know how long they work for ? Just an occasional wipe, or say three times whenever you push the button ? Maybe I should look up the Owners Manual, if for no reason or other than to explain how the heater/cooling system works ? Regards Styria

N.B. Hi Mark, maybe this will help, or possibly add to the confusion - a thread started by Lukas.

http://www.topklasse.org/forums/showthread.php?t=912

 

[Oversize]

Thanks Styria, it sounds like Lukas came to the same conclusion. Now it's just a matter of diagnosing the problem; probably a failed pump. It's actually not all that complicated, but I still scratch my head. It's rather difficult to see what happens when the washer button is depressed (headlights on), so all diagnosis is a two person job. Probably why most owners wouldn't have a clue if they work. Maybe we also need a large mirror as part of our garage equipment? But knowing my luck I'd probably break it and get another seven....

BTW Styria I'm surprised your's aren't hooked up after spending big on that trick aluminum tank.

 

[Tony66_au]

Checked hoses for obstruction and gum?

Id also check the spray nozzles as they are in a high traffic area and may have gooped up.

Id also suggest that if the system has been inoperable for some years the motors will be US Mark.

Id check the hoses with a vacuum pump BTW so you dont force crud to places it does more damage and if they hold any sort of vacuum pressure you have a blockage.

 

[Lukas]

Fixed those images, sorry.

As for the washers - I agree with the others, just poke around with the hoses etc.; as something is likely gummed up.

Styria is right too - to get them to operate, headlights on and then switch on wipers or washer + wipers.

Lukas