Windshield/Headlamps pumps

[revilla]

Hello everybody,

There're 2 tanks, 1 for windshield + 1 for headlamp washing. Each is connected to 1 VDO pump. 

Every time I fill up the one for the headlamps is empty next time I drive the car.  Today I test both pumps and they run fine.  After test, I noticed the headlamp nozzle continued to leak after pump's off.  That explains why the tank goes empty few days after fill up.

I'm assuming the blades in the pump, when static, prevent the water to continue to flow by gravity.  If the blades are deteriorated they don't seal well thus letting water pass towards the nozzle.  Just my theory (?).

Has anybody experienced the same problem?  If so, what's the right fix? New pump? What's the part number?

Thanks a lot for the advice guys.

[djenka018]

Windshield washer system has 1 or 2 poppet valves in line just before the nozzles.

In my case these were stuck blocked.

No reason for these on headlamp washer circuit not to become leaky and then gravity does the rest

[marku]

The pumps have no blades but two brass meshed gears like an oil pump. There appears to be nothing to stop the headlight washers from draining the tank by gravity other than the pump itself. Mine have leaked a small amount and probably need replacing. There is a rubber seal between the two metal plates which forms the actual pump the rest is motor.

[revilla]

Thank you guys.

Seems simple to look for and check these poppet valves. Next weekend I'll look for them around nozzles.  Never noticed them in the hoses for windshield which are fairly exposed.  There most be some too for headlamps.  It seems logic that if they leak gravity will take care of emptying the tank (only applicable to headlamp washer tank; higher elevation compared to nozzle).   If they check OK then I'm looking to replace pump itself as suggested by marku.

Any idea how these little valves look like?  A pic would be much appreciated.

Thanks again.

[marku]

I have never noticed these valves and having stripped out the headlamp washers there were none there. Makes sense to have some sort of none return valve but surely that would be to stop the windscreen washers draining back?

[djenka018]

 Just to make clear, I instigated that there *could be* a non-return valve for headlight washer in the same fashion as those for the windshield to stop the return of the liquid
Something has to stop siphoning the liquid and if it is not present in the pump itself, it has to be in line with the pipework or the nozzle itself

[djenka018]

***

Any idea how these little valves look like?  A pic would be much appreciated.

Thanks again.

Either of these or similar to them.
You can fit one your self if none is present.

[revilla]

Excellent !!! thank you

[marku]

Yes they look ideal and I have no doubt would work really well. But just saying that there is nothing like them on mine and can't think that any one would remove them. Perhaps they were fitted to later models?

[revilla]

Hello everybody,

I can confirm.  Looked at every inch of tubing and couldn't find any of these devices in either of my cars (both w116's).  Which goes back to the pump acting as a "valve" to prevent fluid from running to the headlamps nozzles by gravity.

Any other thoughts/experiences is appreciated.  Please share.

Thx

[djenka018]

Have you tried to run some de-scaler (like the one for coffee machines)?

[Guillaume C]

Hello,
I am surprised that your 280SEL has two tanks. It was only for 450SEL 6.9L because of motor oil tank in front fender.

All the non 6.9L W116 have one tank (with or without headlamp cleaning unit).

The little "stop" valve is present on all my W116 which have headlamp cleaning unit.

[revilla]

Hello Guillaume,

Thanks for your reply. 

Where exactly is that stop valve?  Can you please send me a picture of its location?

Yes, 2 tanks indeed.  1 for windshield washer and the 2nd one for the headlamps (seen in the upper left corner of the pic attached).  It doesn't seem like an after market installation.  It has 2 pumps too, 1 for each function.

Thanks in advance for the help.

[Guillaume C]

I will try to send you a picture of "stop valve".

[revilla]

Thanks for that Guillaume.

If you can detail the location that would be great.

Thanks

Robert