2007 R230.

When I attempt to fill the windshield washer reservoir, a certain amount of fluid appears to go in the reservoir, but then fluid starts spilling out from beneath the undercarriage pan. I don't know how the reservoir is constructed and it's impossible to see without removing the wheel well liners. Anybody got a suggestion as to why the reservoir can't be filled without prematurely overflowing?

Obviously there's a leak ... but is there a known weak point in the system?

Remedy?

It could be one of several things. First, the filler neck is separate from the reservoir and is connected via a rubber grommet. It could have become detached. The reservoir itself could be cracked and leaking. The pumps attach through holes in the reservoir sealed with rubber grommets. These grommets could be bad. Finally, it can also be a bad pump (cracked and leaking).

The best bet is to lift the vehicle and remove the wheel and fender liner extension to access all of this. The pump and grommets are fairly inexpensive, even a whole new reservoir is not too pricey.

Heatwave!
I have the same problem with mine but it holds plenty of fluid without me trying to really get into it. I'll bet it is a filler neck to reservoir leak as mentioned by Rudeney above. I cannot prove that but it makes real good sense to me and I had wondered about the filler neck attachment and if it were a one or two piece deal. Mine holds plenty enough water to keep the warning light off.
moretech

Moretech: My tank situation must be similar to yours. Some washer fluid ... maybe a quart or more ... is staying in the tank. The Low Fluid light has never come on. But it looks like maybe a quart ends up on the garage floor. I'm gonna order a replacement tank and all the trimmings. If one part of the rig is bad, the others can't be too good. When warmer weather is here to stay in a coupla months, I'll take off the wheel and fender liner and find some threads to strip, etc.

Many thanks for your response.

If you can take a pic or two and post them whenever you do the job. It'd sure be helpful to other members besides me. I am real curious about that filler tube connector to the main body. thanks very much.

moretech

Moretech: I'll try taking pix of the work. My limited experience with the camera: I always have so much oil and grease, plus dirt, grit, and general crap on my hands that handling the camera while working is problematic. I'll ask my Superwoman to help with the camera.

As Rudeney indicated, there are a few places on the tank (stress risers at mounts, etc) that look like likely suspects for a break AND, the tank is very inexpensive (less than $60) A2308690020
http://www.mbdirectparts.com/oe-merc...enz/2308690020

here is a picture of one that might shed some light.

http://www.ebay.com/itm/like/142095372758?lpid=82&chn=ps&ul_noapp=true
hope that helps,
Chris

I was looking up something in the Mercedes WIS this morning and "R&R washer reservoir" was included in my search results ... so I thought I'd Post a PDF in case you guys have not gotten to pulling them out yet.

Hope this helps,
Chris

Chris,
Great job on above post. Definitely a bit more complex than one might at 1st think,--- heated system. I never think about that feature as I have never needed to know if it works. thanks again.
moretech

Just a guess based on a review of the .pdf Latemodel21 generously posted for us: the washer fluid leaking I am experiencing probably occurs at the top of the reservoir where the "connecting pipe" joins the reservoir. The "low washer fluid" warning light has never appeared on the dashboard; I take that as a sign that the reservoir is not leaking out.

But ... why does a washer fluid reservoir have to be so complex?

I'm so old, I've had cars that had washer fluid "tanks" that were nothing more than rubber bags attached to the engine-bay side of a front fender. Worked.

Removing the fender liner should allow you to observe how full the tank can be without leaking - which should indicate where the leak is (filler tube, grommet for pump, crack in bottle itself, etc). The R & R document refers to grommets, etc that should be inspected/replaced


"Check rubber grommets on windshield washer fluid pump (M5/1) and
HCS (SRA) pump (M5/2), replace if necessary. "

Hope that helps,
Chris

P.s.
as to the gratuitous complexity of the bottle ... it does maximize otherwise unused space to provide a longish-term supply of not-frozen windshield cleaning fluid. And ... they did not fail much during the warranty period making it a design success by Mercedes standards : )


by contrast to vehicles of old ... my 65 GTO (I bought when I was 15) had so much room in the engine compartment, you could nearly sit inside while adjusting the carburetors .... AND yet, it did not have a windshield washer bottle because it did not have squirters (an option the original purchaser passed on)

I just re-read your post and it makes sense that if you never get a low fluid light that the leak is at or above the sensor ... so the connector from the tank to the filler pipe would be the number one suspect (#110 in drawing, A230 869 01 17 ), or, there is a gasket between the filler tube and the connector (#115, A230 869 0098) and the level switch has a grommet (#100, A230 997 1981).

hope that helps
Chris

Thank you, Chris, for the blow-up diagram. That is most useful. I printed it and placed it in my ever-expanding R230 3-ring binder.

With that washer fluid bag, you would not have heated fluid to de-ice the windshield, nor would you know when it was empty, and you would not be able to use it to wash your headlights. Gosh, that just sounds like the dark ages.

I had a '65 and a'67 Lincoln with the small plastic bags for fluid. But what is SAD is that I am old enough to have actually used them routinely. Time does fly.

moretech

Moretech: I had a '56 Ford Crown Victoria. Black over white. Plastic washer fluid bag, vacuum-operated wipers, 6 v. electricals. It was a different age. I was too.

After filling my windshield washer reservoir, some NOT all of the fluid will leak out from underneath. I cannot see where it is leaking and the low fluid light will go out when I fill the reservoir but quickly comes on after it somewhat drains. Not all of the fluid drains. I currently just keep the fluid low, which causes the indicator light to be on. Any thoughts where to start first?

I don't want to sound like a wise guy, but the place to start would be reading this thread. I think it's covered here.

The reservoir in my W113 is real hybrid. Shaped like a bag but in fact made of hard-ish plastic. 1966 electric pump just pumps, and pumps. Built to last.

I just replaced a windshield washer pump in my SL. It did not work at all, and on top of this, the fluid leaked when I tried to top off the tank. So I removed the tank. I totally do not believe that it can be done per the WIS above. There is no way to pull the pumps up as directed in the step 3. I also did not disconnect coolant hoses. First I opened the cap with heater hoses, so the heater was loose inside the tank. After that I just removed the entire tank with all attached stuff. Then pulled off hoses leading to the windshield and front bumper. Then wiggled the heater out of the tank (be careful not to sheer off the level switch inside). If you need to disconnect pump connectors - put small screwdriver into the opening on the side of the connector and push the handle up, tip will press down and away on the tab inside disengaging it. To make the job easier start by backing off two screws holding black grill in the right front fender. No need to remove the grill itself, it is just that these screws protrude inside and get in the way. I am not sure if leak was from the filler tube connection or from heating tubes' seals, but either way it is only possible when tank is completely full. Hope it helps someone. Pump was $10 (not a genuine MBZ). Should have also ordered filler tube and grommet mentioned in one of the posts.

Found my leak at the top of reservoir. Easy fix! Replaced motor and gromit. fuse is good. Washer still not spraying. Any other recommendations? Head light spray works great.

Windshield washers and headlight washers are fed by two different pumps. Make sure that you replaced the correct one. Start by listening if pump even runs when you turn on the washer.

Hello. I have had the same symptoms for a while in my SL55 AMG, i.e., about a pint of water runs out the bottom of the car after filling the reservoir to the top. After reading this thread and above quote, I thought the problem was probably the O-ring gasket in the accordion pipe that joins the filler neck to the tank (#115 in the diagram, PN A230 869 0098).

After inspecting the pipe, I found that there was no O-ring in the joint (where it went, I have no idea), so I assumed that was the culprit. I ordered one from the dealer thinking that would be it. The foam gasket looks very flimsy and came with some creases in it. I cannot see how this setup would be water tight, but okay, I installed it (fighting the urge to use silicone to seal it). After re-assembly, the pipe area leaked exactly as before.

During this effort, I did not pull the entire accordion hose (#110 in diagram, PN A230 869 01 17) all the way out of the tank since I did not know how it seals itself to the tank (it seemed awfully loose). So my question is, does part #110 seal to the tank with a simple O-ring, or is there more to the joint to make it water tight? It seems very poorly designed.

Thanks,
Robert

PS: I have included photos of the gasket for anyone who reads this, in case they want to make their own to improve on what the dealer offers.

Sorry to revisit this thread but searching for windshield washer problems keeps bringing me to this thread. My 2012 SL63 AMG has been sitting for 5-8 months thanks to this covid *****. Yesterday being a beautiful day I deceided to start it up and check things out. As soon as I put the key into the switch the washer started pumping spraying fluid all over. The engine started OK but the washer kept pumping until it was empty and still kept pumping. Some troubleshooting showed the battery in the trunk was dead. I replaced it today and am still having all kind of problems, mainly the washer pump running along with lights being on, windows not working properly etc. Any ideas? I pulled the fuse in the engine compartment (f14 7.5 amp) and it kept running. I must note that inside the fuse box was wet which I dried the best I could and blew it out with air. Is there anything else on that side of the car that could be what I'm hearing? Under the battery.

In the diagram above what is 230, 900, 901 on the hose attached to the pump?

Mine didn't have it and I see some dried washer fluid at the resulting hole near the pump. I am guessing some sort of pressure release drain that opens with no pressure allowing fluid to drain from nozzle hose but closes when the pump is on to force fluid to nozzles.

Thinking my valve (if it is one) may leak slowly draining the tank?

The front headlight washers may also be the culprit but it would have to siphon as the pressure hose goes up above the tank.