Washer fluid resevoir

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Guys, spotted a slight leak coming from one of the pumps (headlamp wash) attached to the reservoir. I say slight because it's barely a drip but enough to notice. From what i can make out there are 2 pumps, one on left being winsdshield and right for headlamps? It looks like it's coming from the base of the right pump. Is there a quick fix to this?? Do i need a new resevoir or just a pump? I'm a bit concern since about to go on a winter road trip over the holidays, and with the kind of winter we're getting at the moment, the last thing i need is running out fluid while on the highway.

Since last topped up, sitting in the garage, about 4 days ago i may have lost 1/2 of a cup. Less than 1/3 of the reservoir, so not too bad. But can't stand fluid leaks!

 

[gerryvz]

Generally, this is because of a degradation in the rubber grommet that presses into the base of the washer reservoir. The pickup nozzle of the pump then presses into this rubber grommet.

Go to your dealer parts department, and ask for part number 123 997 36 81. These typically cost about GBP 2 apiece. Get about 5 or 6 of them because you will be replacing them repeatedly over the years.

Then, either siphon out your reservoir, or pull the pump up out of the grommet and let it spill out/drain. If you don't know the age/type of fluid, I'd just drain it and replace it with MB fluid, which you can also get at the dealer for about GBP 3-4 for a vial that makes 4 liters.

Then, you'll probably need to remove the reservoir from the car. Unhook all of the electrical connections to the pumps and remove the hoses. Then after you get the reservoir out, pull out the grommets and replace them with the new ones by pressing them into the holes. Then re-install the reservoir and then press the pumps back into the grommets. Should be a nice tight/snug fit, and no leakage. Then, reconnect everything as you removed it. Then mix up a batch of the washer fluid and fill the reservoir with it. I use a washed-out plastic one-gallon milk jug for this purpose.

Note that MB has different fluids for summer and winter use. The winter one is designed for colder temperatures.

It can be a good idea to get a new pump too, but generally the grommet replacement will suffice. More on the pump is here: viewtopic.php?f=11&t=983

Cheers,
Gerry



Here is the vial of fluid w/part number:

 

[gsxr]

It can be a good idea to get a new pump too, but generally the grommet replacement will suffice. More on the pump is here: viewtopic.php?f=11&t=983

The old/original pumps leak more often than you might think. If you replace the grommets and still have a leak that seems to be coming from the grommets... chances are it's the pump itself. I've had to replace both pumps on most of my W124 fleet in the past few years. They start leaking at the bottom, out the pump body itself.

As a rough test - if you can blow into the base of the pump while blocking the outlet, and it's not perfectly airtight, the pump is defective / leaking. A more definitive test can be done via a MItyVac that builds pressure, the pumps should hold ~5psi with zero leakdown. On my cars, new pumps & grommets have always fixed the leak. New hose is often in order, so if the old hose is fossilized, consider that as well. Sometimes the pump hose fitting will snap off as you're trying to remove the old hose! BT, DT...

 

[gerryvz]

Yes indeed, I've had pumps go bad as well. I'd say that 80% of the time it's been the grommets though. I just got the parts to replace one of the pumps on my wife's E320 wagon. I got the pump as a proactive maintenance thing, but I realize that not everyone takes that approach.

Cheers,
Gerry

 

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gerry, thanks! since i'm pulling the pumps out i may as well replace them. on my way to get the bits now!

 

[bing]

guys, any other source of leak aside from the above??

the car sat for 2weeks and the resevoir was completely drained
I've replaced the grommets back in december and all seems fine till this weekend. don't think it's the pumps as it should'nt drain entirely when not being used (or will it??), plus i can't see any traces coming from the pump/grommet area. could the tank itself has a crack somewhere??

 

[gerryvz]

My best guess is not a good seal with the grommet(s). You need to fill it up again (just use water, heck) and then take a look to see WHERE it is leaking from. Generally a flashlight will tell you all you need to know. Sometimes you don't get a good seal between the grommet and pump and need to remove and re-press it in.

Did you put a new grommet in?
Did you install a new pump?
Did you check to see WHERE the leak is located at?

cheers,
Gerry

 

[gsxr]

guys, any other source of leak aside from the above??

the car sat for 2weeks and the resevoir was completely drained
I've replaced the grommets back in december and all seems fine till this weekend. don't think it's the pumps as it should'nt drain entirely when not being used (or will it??), plus i can't see any traces coming from the pump/grommet area. could the tank itself has a crack somewhere??

If the reservoir is TOTALLY empty - as in dry, no liquid - the reservoir must have a crack or hole and will need to be replaced. If the reservoir is drained down to the level of the grommet area (maybe 1-2 inches of liquid remaining), it's either the grommet or the pump(s), or a bad connection at the hose barb.

As I said before: EVERY one of my cars had at least one bad pump which would leak, even with new grommets. If you have not replaced the pumps - replace both.

 

[Jim]

The water could have siphoned out of the headlight water jets due to a defective valve in the line.

 

[bing]

The reservoir was dry, way below the pumps/grommets!

Grommets replaced twice in the last 3months but not the pumps.

I've topped it up, and so far in the last 2days, the level has not gone down but i can see dry traces underneath the tank itself(but maybe over spills when i topped it up since it's dry blue traces). None around the pumps, bone dry. Also squirted a few times to see if it becomes more apparent and fresh fluid coming out but nothing! Ordered a new 'reservoir' already and perhaps i should replace the pumps also? If it's the reservoir, then this is new to me as I can't understand how this can crack. As Dave says, I can't see the pumps/grommets being the cause as it should still have a bit left if it were. PITA!!

 

[500ESpain]

I once had a leak after driving on a very bumpy road. One of the rubber pipes that go from the pump to the washer jet came loose draining the whole reservoir.

 

[DerFuror]

Re: Leaky headlamp washer fluid pump grommet

I recently replaced the headlight washer pump grommet & hose. I noticed a slow leak emanating from the pump base while conducting my Euro headlight conversion. Reservoir removal was unnecessary.

Recommendations:
• If you are converting to Euro headlights, consider concurrent replacement of old headlamp washer circuit parts also (you’ll never have better access to everything at one time again!)

• Order a new hose (010 997 89 82) along with the replacement grommet (123 997 36 81). The hose is sold in a meter length. A half meter is required (use the other half on your other E500E or store the remainder in a Ziploc bag for future use).

• Siphon as much washer fluid out of the reservoir as possible (at least below the pump feed level).

• Slide the hose clamp down off the pump connection bib using pliers. Cut the old hose off (don’t risk breaking the bib). Cut the remainder off the bib using a razor blade.

• (Although the pump can be removed by hand) A body trim removal tool worked perfectly to lever the pump straight up out of the grommet.

• Wipe the reservoir base at the grommet hole clean prior to new grommet installation.

• Transfer the old hose clamp onto the new hose. Soften the new hose end using a heat gun prior to reconnecting to pump hose bib.

• If you are not converting headlights, access the other end of the washer hose from under the car behind the bumper. Removal of several hose clamps (000 995 60 44) from their body mounting holes will ease this process. Pull the check valve down toward you. As with the pump, cut the old hose off & cut the remainder off the bib using a razor blade. Soften the new hose end using a heat gun prior to reconnecting to check valve hose bib. Once connected, push check valve back into place. Reconnect hose clamps.

 

[gsxr]

Nice writeup, Derf! Tip: If you get a leak at the pump even with a new grommet, it's 99% likely the pump body is leaking. A new pump will cure it. I've had to replace both pumps on almost every one of my 124's to stop the pesky leaks. Be careful with the other pump (for the windshield), that hose is heated and has wires in it... difficult to remove & re-attach, etc. Don't touch it if it's not leaking.

 

[bing]

Nice writeup, Derf! Tip: If you get a leak at the pump even with a new grommet, it's 99% likely the pump body is leaking. A new pump will cure it. I've had to replace both pumps on almost every one of my 124's to stop the pesky leaks. Be careful with the other pump (for the windshield), that hose is heated and has wires in it... difficult to remove & re-attach, etc. Don't touch it if it's not leaking.

Tell me about it! In the end I replaced both pumps and tank. Yes, that heated hose to windshield pump was PITA to re-attach. Not even sure if this particular hose is still available as I remember trying to order one but MB parts couldn't find it. So far no leaks.

 

[gerryvz]

Derf, it looks like your leak pump was already a replacement (the 129 number and black color is a giveaway). The original pumps were white in color and had a 124 part number; the current pumps (at least those spec'd from the last 4-5 years) use a 202 part number and are also black in color.

For longest life from the pump and grommets, be sure to use the MB washer mix ... either the "winter" or "summer" variety. They only sell the summer type here in Houston at the dealers, but you can order either kind and I'm sure it's readily available in your neck of the woods. There are chemical formulations on the off the shelf products that I just don't trust (harsh) and I believe they may shorten the life of our washer pumps.

The hose is available, yes. I just got some hose in a 1m length a few weeks ago from my local dealer, and it was black in color !! So I would recommend, if you are in the US, to go with an aftermarket supplier like AutohausAZ and get the white hose if possible, as it is the same as the original hoses. And you might be able to get it in greater lengths than 1m. I keep a few lengths handy to use as siphons for coolant tank, washer reservoir, gas tank, etc. and it works well for that.

Seems that every couple of years I'm replacing a pump - just had to do one of the pumps on my E500 several weeks ago as the pump body was leaking. It was the original pump though, so I can't complain. Several years ago I purchased like 20 of the pump grommets as they are cheap, and have to be replaced with enough regularity that it made sense to have them on hand. Same thing with the shift linkage bushings. I just buy 10 at a time because between all 4 of my cars (which have 722.3s) I go through 1-2 bushings every couple of years... or end up giving one or two to a friend in need.

Two soft parts it's nice to have on hand. I also keep an extra washer pump in stock, "just in case."

In the attached photos, from last month, you can see old and new grommet inside diameters, old and new pumps side by side, and old (fossilized) and new pump hose lengths. The yellow/brown hose is the original E500 hose.

Cheers,
Gerry

 

[gsxr]

FYI. The hose is different for the windshield fluid line vs the headlight fluid line:

The windshield hose is larger O.D. and comes in a fixed length, and it's not cheap. I haven't heard anything about it not being available so I'm assuming it still is, although until someone checks stock with a dealership, we won't know for sure.

The headlight washer hose is the standard vinyl tubing shown in the bottom photo of the post above. IIRC, the aftermarket hose is clear, and the OE hose is now black. This hose is sold by the meter and you may want to replace some or all of it when messing with the pump replacement, and/or headlight wiper panels (i.e., when converting from USA to Euro lights & wipers).

One thing I haven't been able to find is the tiny spring clamps used at the hose ends on the pumps. Most of my cars had these from the factory but the clamp isn't shown in the EPC.

 

[DerFuror]

For longest life from the pump and grommets, be sure to use the MB washer mix... and I'm sure it's readily available in your neck of the woods. There are chemical formulations on the off the shelf products that I just don't trust (harsh) and I believe they may shorten the life of our washer pumps.

My woods are deep, dark, inhabited by strange minions and located many leagues from any dealership. I ordered the washer mix from parts.com once, but it sells by the case, not individually, so I opted out of the purchase...it is amazing how much fluid the reservoir can contain! Be prepared with a couple empty gallon jugs if planning to siphon out a full reservoir.

The hose is available, yes. I just got some hose in a 1m length a few weeks ago from my local dealer, and it was black in color !!

Yes, the new generation hose is black. I kinda like the black hose going from pump to check valve. It's almost invisible to the eye & won't turn krusty yellow. But it does seem the white/clear hose has a larger OD than the black...which leads to this question...what route does your hose take on route from pump to check valve? Does it pass thru the plastic headlight bucket (as show in attached pic)? I don't think a white/clear hose can pass thru this same hole.

...you can see old and new grommet inside diameters...

My grommets looked exactly the same. The old grommet was still very pliable, only its ID had become permanently reamed oversize over time. The leak started after I disturbed its sedentary lifestyle during the headlight conversion. I tossed it into my grommet bin. It can be re-purposed for some later project.

 

[bing]

Derf, it looks like your leak pump was already a replacement (the 129 number and black color is a giveaway). The original pumps were white in color and had a 124 part number; the current pumps (at least those spec'd from the last 4-5 years) use a 202 part number and are also black in color.

Yes, well spotted, Uncle Gerry!

For longest life from the pump and grommets, be sure to use the MB washer mix ... either the "winter" or "summer" variety. They only sell the summer type here in Houston at the dealers, but you can order either kind and I'm sure it's readily available in your neck of the woods. There are chemical formulations on the off the shelf products that I just don't trust (harsh) and I believe they may shorten the life of our washer pump.

My parts guys said the same thing but thought he was just trying to sell me MB brand. So it's a possible cause that shortens life of the pumps.

Seems that every couple of years I'm replacing a pump - just had to do one of the pumps on my E500 several weeks ago as the pump body was leaking. It was the original pump though, so I can't complain.

Are you now using MB washer solution? If so, let's see if the pumps/grommets last more than 2 years.

FYI. The hose is different for the windshield fluid line vs the headlight fluid line:

The windshield hose is larger O.D. and comes in a fixed length, and it's not cheap. I haven't heard anything about it not being available so I'm assuming it still is, although until someone checks stock with a dealership, we won't know for sure.

One thing I haven't been able to find is the tiny spring clamps used at the hose ends on the pumps. Most of my cars had these from the factory but the clamp isn't shown in the EPC.

Both of the above, MB parts couldn't find them in the EPC. Didn't pursue as I didn't really need them(not yet anyway)but would have been nice to replace since I was there doing a complete R&R.

 

[gerryvz]

My white hose does pass through the hole on the plastic headlight bucket en route to the check valve, yes.

Having a new check valve on hand is not a bad idea too -- there are a couple used for the various washer systems. They can and do go out.

 

[DerFuror]

My white hose does pass through the hole on the plastic headlight bucket en route to the check valve, yes.

Good to know. Thanks for verifying.

 

[gsxr]

The fixed-length hose for the windshield squirters is on page 2 of group 86 (second photo), part number is 124-860-00-92, current MSRP is $81.

The spring clamps are shown in this photo as well, however they have been superceded to a new/different number that is a single-use clamp that requires a special tool for installation.

 

[jano]

This is good timing. I swapped out the grommets on my '94 e500 and initially it appeared the leaking stopped. I monitored it for several weeks (6-8 or so), didn't see any leaks anywhere, and used the washer fluid a handul of times. The car sat for about 3 weeks while I played with my other w124, and when I got back into the e500, there was no fluid whatsoever. I'm planning on installing new pumps, methinks I'll go with the oem pumps, instead of the myle ones on autohausaz. Should I consider the reservoir as well? I've got a feeling it may be cracked and has a slight seep. Is it hard to replace the reservoir?

 

[gsxr]

The new reservoirs are slightly different and are not plug & play... unless your old reservoir is definitely damaged, I'd leave it alone. The leak is 99.9999% certain to be fixed with new pumps, grommets, and a good hose connection.

 

[gerryvz]

Reservoirs are easy to replace. I have a spare/new one if you want to buy it. They're not all that expensive from parts.com. DO NOT get the cheap Meyle pumps -- get the real deal from MB. That Meyle stuff is junk. They're not that much more than the Meyle jobs if you order via parts.com/BMWMercedesparts.com

You can see the part numbers in the other thread on the topic. As I said, get a bunch of grommets so that you have them handy when you need them. They only last a few years before needing to be replaced, particularly if you live in a hot climate.

If you want the pumps and grommets NOW, your local dealer will definitely have them in stock. But you will pay nearly double that you'd pay via parts.com, as they dealers tend to mark them up.

Cheers,
Gerry

 

[bing]

This is good timing. I swapped out the grommets on my '94 e500 and initially it appeared the leaking stopped. I monitored it for several weeks (6-8 or so), didn't see any leaks anywhere, and used the washer fluid a handul of times. The car sat for about 3 weeks while I played with my other w124, and when I got back into the e500, there was no fluid whatsoever. I'm planning on installing new pumps, methinks I'll go with the oem pumps, instead of the myle ones on autohausaz. Should I consider the reservoir as well? I've got a feeling it may be cracked and has a slight seep. Is it hard to replace the reservoir?

Yep, sounds familiar. Exactly what used to happen to mine - sat for 3weeks and empty. Changed the pumps, Grommets and tank as I got fed up! Though I think the tank was fine, so I would just change the pump first.

The new reservoirs are slightly different and are not plug & play... unless your old reservoir is definitely damaged, I'd leave it alone. The leak is 99.9999% certain to be fixed with new pumps, grommets, and a good hose connection.

Some truth in this. My new tank wouldn't sit properly , had to press down hard in order for the long plastic nut to bite! Again, start with the pumps. If it still sleaks then go for it (at least you'll only waste a set of grommets and fluid) and you'll have a nice new white tank.

 

[gsxr]

Yep, the new tank has a slightly different shaped bottom protrusion and it won't fully seat by about 5mm or so. Not a huge deal but if you're picky, some minor mods are needed. After my initial experience, I leave the washer tanks alone unless there is a really good reason to replace it...

 

[TerryA]

bing,

I recently replaced both of my pumps. When I went to replace the rubber gromets I discovered that the leak was partially due to a cracked tube on one pump and the other was to short to get a good seal.
I purchased two brand new aftermarket German pumps for half the price of the MB OEM pumps @ $18.00 each. They looked exactly like the originals w/o the MB stamp.

Anyway after removing the water tank and completely tearing it apart for cleaning (including the heating element). I re-assembled it with all new gromets and pumps.

It still had a leak at the new pump to the heated hose to the windshield. This heatedhose becomes hard over time and does not clamp well with the OEM MB clamp.
The OEM clamp is to weak to squeeze down on the hose. I stopped the leak by using a small aircraft style clamp.

You might want to examine that hose for a good fit.

Take Care

 

[gsxr]

I had a similar issue, Terry. What I did was carefully (!!!) trim the heated hose about 0.5-1.0 inches back, not cutting the wires, just the vinyl tube. This allowed the pump to plug into a portion of softer, unswollen hose for a leak-free fit. Otherwise your solution is a good alternate, adding an aftermarket clamp.

 

[TerryA]

Dave,

I was concerned about trimming the hose. It already seemed short. The clamp doesn't bother me. I am not entering any concourse event to be judged.

BTW I put in the two pumps but the one is just for looks. I have the wiper delete panels under my lights. I plugged the hose to the wipers with bolt clamped into the hose end and tucked it away.

Have a great weekend.

Take Care

 

[gsxr]

Yeah, that's the problem, the hose is short from the factory! There is almost zero additional length to work with. You've got maybe 1 inch total to play with, after that, you're buying a new hose (or maybe adding a piece with a plastic connector).

 

[jano]

Just a heads up to anyone doing this, don't ask how I found out: the washer pumps appear to be normally open when not powered.

You can't put a new pump in with the intent of replacing the inflexible headlight washer fluid line that won't slide over the new pump at a later date, without putting on a new line that's clamped or closed.

Hrrrmph.

 

[ghm]

Some good maintenance information here, I hope everyone is periodically checking around the washer fluid tank for leaks. I was looking at my 300E, which has the same setup as my 500E, and found fluid/rust under the tank. I changed the pump grommets only 2 or 3 years ago but they were shot, the windshield washer fluid must really be bad for them. I hope new pump grommets fix the leak, otherwise I will replace the pumps as well.

In order to address the rust issue I had to remove the large grommet that the tank sits in. Of course it came out in several parts and needed replacing. It does appear that over many years the tank eroded the paint where it contacts the car body which made the area prone to rust, with or without a fluid leak. Fortunately the rust was not bad and some sanding and rustoleum seem to have done the trick. Photos below show the area under the tank immediately after removing it and the replacement grommet that fits into the car body and locates the washer fluid tank.

 

[vatc5637]

It is likely that new grommets or washer pumps will stop the leak. However, if they don't, check the reservoir itself, especially near where the heating unit attaches to the wall of the tank. I've had to replace 2 tanks because of visually imperceptible cracks, probably caused by constant movement of the heating element combined with aging plastic.