Stupid washer bottle syphons itself empty - whats up?

[B13]

Like the subject says, the washer bottle syphons itself empty.

The bottle itself is not cracked / has no holes in it... if you fill it with water and don't use the windscreen washer it will not empty itself. But lately if I use the windscreen washer it will then empty itself at a rate of approx. 1 drop every 5 seconds, until empty. The puddle on the garage floor is roughly beneath where the power steering pump is (more or less).

Any ideas?

I.

 

[WGB]

Might be as simple as a leaky join or a crack in a hose.

Once the tube is primed it will keep draining.

Might be more complicated like a leaky pump - but same principle.

Bill

 

[OzBenzHead]

I had a similar mystery - first in my 116 and later in my 108. I checked and double-checked and was utterly mystified.

Then I discovered that the pump was leaking - just the tiniest bit, almost too little to see. If left unused for a few weeks, it wouldn't leak, but as soon as I used the washers, the leak opened up again. I replaced the pump and all was well. Perhaps I could have dismantled and re-sealed the pump, but I didn't bother (though I have kept it with that possibility in mind for a rainy day).

Oh, and once the leak re-started, it would drain the tank dry within the day, despite no further use of the washers.

 

[BAR]

As has been suggested by others, the problem generally lies at the pump or the hose connections to it.

These units are now around 30 years old, all the fluid and detergents passing through them, plus the heat from the engine bay has the effect of drying out the plastics. With mine it was the connection to the pump that corroded, not a hose.

You can try to buy a replacement Mercedes pump, or a cheap alternative is to go to an Auto Parts place like Repco, Autobahn etc and get a generic pump that can be attached to the car, these are around $10.

It's obvious which hose is inlet and outlet when removing the old pump, so just make sure that the hoses are attached to the replacement pump correctly and you are back in business.

You may find that it is an easier task to replace, after removing the battery tray, poor location of the pump in the 450's. Take the opportunity to wash out the Battery tray and clean up the bodywork around the area at the same time.

 

[B13]

I'm going to have a look at it on the weekend.

Was aware of the strange place for the washer motor under the battery tray on the W116, which is why I was curious that the puddle which forms under the car is on the other side roughly under the power steering pump...

Thanks for the responses.

Ian.

 

[WGB]

Pump is under the battery tray on a 450 and under hydraulic reservoir on opposite side on a RHD 6.9.

I'm assuming it is your 6.9 so it will be leaking either from a pump or a connection.

Bill

 

[B13]

Yes its my 6.9

I wouldn't expect anything less of MB than to put items in hardly accessable places on special limited edition vehicles like the 6.9

I like where it is on the 450,,, battery out, tray out and you have good access to the washer pump/motor...

But I've been thinking to remove the hydro tank and clean the thing, renew the hoses etc., so this might be a good time to fix the washer pump/motor and change its hoses.

If the hydro suspension doesn't come good after the next attempt to sort it out, its getting the flick...

I.

 

[WGB]

You and Des sure have had a lot of trouble with that car's suspension and I offer my sympathy but the answer must be there somewhere.

Is it still down at the front?

Might be a time for another posting ofteh problems and try again with some collective wisdom.

I can't really remember if the washer pump is inaccessible or not.

I know the one in my car was loose and rattling on it's mounts and that I tightened it up while replacing the LH headlamp unit with a better one and spotted the loose pump at the time.

I removed the inspection hatch at the back of the light nacelle and tightened it up that way. Latterly I took out the hydraulic tank to clean it but never touched the pump.

The reason it is on the opposite side to a 450 is because the oil tank for the dry sump on a 6.9 fills the place of the 450 bottle and the bottle is shifted to the opposite side.

Bill

 

[TJ 450]

On the 6.9, the washer pumps can be accessed with the charcoal canister and panel below the headlight removed. It is even of further benifit to remove the suspension reservoir bracket.
IMHO you should perform both jobs at once... pressure regulator/distribution valve o-rings, filters and all hoses on the low pressure side and clean out/lube washer pumps. This will ensure everything is covered.

Tim