Screen washers only dribbling

[lordksmith]

Morning everyone, I have a problem in that my screen washers have very little or no pressure ,but my headlamp washers are so powerful they wash the lights and the screen. My question is, are there two separate motors or one, with two pickup's or is it possible just partially blocked jets.
This appeared to start recently after I raised the bonnet to vertical,possible coincidence as I can't see any visible leaks.

 

[LostKiwi]

It may be a kinked damaged hose going to the screen washers or blocked nozzles.
It may also be a tired washer motor (they are separate).

Start with the simple stuff and with a fine needle have a poke in the washer jets to see if there is a blockage. Often the nozzle will block and with 5-10 mins of jiggling with a needle clear.

 

[Craiglxviii]

Two separate motors. The lamp washer jets are activated by water pressure = HP pump. Windscreen washer jets use LP pump.

My CL has the dribbling-wee problem too, I've replaced both pumps recently (both used parts) and although it fixed the headlamp washer issue, it didn't fix the windscreen washer issue. So I'm intrigued myself, maybe I need to spend some more money on a new pump.

 

[DREAMER NO2]

Polish is the main problem .As you clean the car it gets in to the very small jets .I use a blow lamp pricker to open them up.

 

[lordksmith]

Thanks chaps, I'll start with the sharp pin option, then pipes, then possible motor.

 

[EmilysDad]

Thanks chaps, I'll start with the sharp pin option, then pipes, then possible motor.

I've never had need to look on my Merc, but if it's all screen washer jets, I'd suspect either the pump as you say (but there's little inside a pump that could fail) or, on my previous cars, the pump sucked through a filter in the tank which gunges up .... generally with algea that builds up due to cheap or no screen wash.
But if your problems started since you lifted the bonnet to its highest position it could just be a kinked tube to the back of the bonnet.

 

[LostKiwi]

I've never had need to look on my Merc, but if it's all screen washer jets, I'd suspect either the pump as you say (but there's little inside a pump that could fail) or, on my previous cars, the pump sucked through a filter in the tank which gunges up .... generally with algea that builds up due to cheap or no screen wash.
But if your problems started since you lifted the bonnet to its highest position it could just be a kinked tube to the back of the bonnet.

If you have algae drop in a miltons tablet (the stuff they use to sterilise baby's bottles). Works a treat.

 

[EmilysDad]

If you have algae drop in a miltons tablet (the stuff they use to sterilise baby's bottles). Works a treat.

I use a decent screen wash

 

[Naraic]

I suspect what has happened is a pipe has pulled off one of the washer jet installations, thus there is no pressure to both of them. It will not be the need for a pin, nor the motor.

Open your bonnet and observe what happens when you squirt the water...if a lot comes out underneath the bonnet this is what has happened.

Reconnect the pipe.

 

[Naraic]

Two separate motors. The lamp washer jets are activated by water pressure = HP pump. Windscreen washer jets use LP pump.

My CL has the dribbling-wee problem too, I've replaced both pumps recently (both used parts) and although it fixed the headlamp washer issue, it didn't fix the windscreen washer issue. So I'm intrigued myself, maybe I need to spend some more money on a new pump.

As above...check the pipe connections to the squirters.

 

[lordksmith]

Jets blocked with polish and other "crud', and yes one of the pipes had come a little loose, surprising what a difference it made. Still all OK again now, I will just be a little more careful lifting the bonnet to vertical the next time.

 

[philharve]

Windscreen washer jet unblocker

For what it's worth, you can buy a set of needles of different sizes specifically for unblocking jets on eBay. I've used mine a few times but they are mostly used by friends who know I have them. Current price <£5. They usually buy me a coffee in gratitude.

 

[turbopete]

check to see if theres a filter on the end of the pump where it goes into the washer bottle. Ford have used one for over 20 years now and if you are one of those people who never lets their washers run out every so often, a sludge forms (similar to in a pond) and covers the filter preventing water getting through and low pressure. its a pain to remove and clean in some cases, but better than going through the pump and up to the washer jets I feel. as a result I tend to let mine run out before refilling (and before anyone says it, I do carry some fluid with me once the low fluid warning comes on, so I can stop and refill as soon as the washers run dry)

 

[philharve]

Does the washer bottle have to be removed to clean the sludge out?

 

[turbopete]

ive never had to take one out, usually pop out the pump and the filter/grommet and let the bottle drain. fill it with plain water if its not full first to give it an extra flush through, then refit and refill. ive no idea if there is a filter in the MB washer bottles but on the Fords it is the fault EVERY time, unless the pump has failed (or at least ive never had one that cleaning the filter DIDNT cure, even when I was in the dealers)

 

[philharve]

I took a look at my C230K windscreen washer jets today and poked around with a miniature needle file and the jets appear open and clear of crud. I emptied the washer reservoir and refilled with MB washer concentrate in the 1:2 ratio. I found the reservoir clean and apparently free of algae although I didn't examine the filter, which I think requires the pump to be removed first.

When I came to test the washers there was no improvement. The passenger side jets are weak but they continue to squirt as long as stalk control is pressed. The driver's side jets squirt just once as the stalk control is pressed then cease altogether. There are no leaks anywhere. I have come to the conclusion that maybe the tubing between the pump and jets is kinked or clogged somewhere or that the pump is not working at optimum efficiency. The pump makes all the right sounds and water is being ejected from the jets but apparently at low pressure.

I haven't yet figured out why the response from the jets are different, passenger versus driver side, unless something has happened to the washer tubing within the bonnet but I don't see how that's possible.

I have a new Febi pump which I could install and replacement looks easy if a little cramped. I don't see how the pump remains in place. Is it an interference fit as the pump's inlet tube is inserted into the reservoir?

If a new pump doesn't fix the washers, how easy it to access the tubing inside the bonnet, which appears to be double-skinned? There is some kind of flexible heat shielding covering the lower face of the bonnet, which I assume this will simply pull away when the retaining clips are removed?

I have a small air compressor and I was wondering if I could use it in place of fluid to check the path between pump where it couples to the tubing and jets? Are there any non-return valves in this 'liquid circuit' so that liquid pumped into the tubing remains in the tubing when the pump in inactive? Maybe the pump acts as a non-return valve?

Am I correct in assuming that to access the filter the pump has to be removed? There is no access to the filter from inside the reservoir as far as I can see.

 

[EmilysDad]

....
Am I correct in assuming that to access the filter the pump has to be removed? There is no access to the filter from inside the reservoir as far as I can see.

Never done the Merc's washer system, but though this guide clicky is for a mere Vauxhall, I'd guess it's similar ..... even Emily's Siecento is very similar.

If the pump is making all the right noises, it does sound as though the filter could be blocked.

 

[philharve]

If you are correct and the filter is blocked, it looks as though I have to remove the pump to get at the filter.

tubopete mentioned 'filter/grommet', which rings true to me. If I extract the pump, the grommet into which the pump inlet inserts, can be removed along with the filter. Flushing with water should remove any algae. Refitting is the reverse: insert filter/grommet then insert the pump. Couldn't be easier. I will lose the fresh windscreen washer fluid I have put in but I have plenty more.

In reply to other comments ... the only fluid leaks are from the jets, which disproves there being a leak in the tubing between pump and jets. I am still trying to get my mind around the possibility that there could be a blockage in the tubing. It just doesn't seem possible.

I have discounted the possibility, up until now, that it could be a fault with the pump which can take one of several forms. Maybe the pump cannot deliver washer fluid to the jets at the correct pressure any more. The pump must be an original component in this 16yr old Mercedes. Very recently I replaced the fan heater in the same vehicle. Its brushes had worn out.

I am still mystified as to why the passenger side receives a jet of fluid but the drivers side receives one squirt which each depression of the stalk control. Could it be the path of the tubing from the pump goes to the passenger side jet first then onto the drivers side jet? This could bring about different pressures at each jet and the odd behaviour. There must be a 'Y' splitter in the tubing somewhere. I wonder where within the bonnet it is?

I will take a look at the Vauxhall link you provided. It might give me food for thought. Thanks.

 

[philharve]

OK, I had a quick look. The Vauxhall has a twin pump system: one for windscreen, the other for headlamps. My C230K has a single pump. The advice from the Vauxhall link is as follows. I can easily identify with it. It confirms what turbojet has stated ...

"Tilt top of windscreen pump towards back of car to unclip, then lift up and withdraw. Where the pump has come out from, there is a rubber grommet - remove this. (Its likely at this point that the washer bottle will empty through this hole). This grommet has a built in filter - clean this out under a tap, ensuring it is completely clear. Refit is the opposite, ensure that grommet and pump are properly seated to stop leaking."

I'm not sure if the pump is clamped in anyway to the reservoir but if we ignore the reference to 'clip' then the description that follows is the same for my Mercedes ... including the mention of losing the washer fluid.

I think my next step is to examine the filter and, if necessary, replace the pump. I am making the assumption the filter, a very simple component, can be reused.

 

[philharve]

I had a quick look around to see if I could find a photo showing how the windscreen washer pump attaches the the washer reservoir and I found one. The reservoir in the photo is not the one in my C230K but it does show that the pump is held by the reservoir itself. There are no clips to worry about. Replacement of the pump should be simplicity itself. However, access to the pump maybe a little restricted. I assume the grommet houses or incorporates the filter. The grommet also prevents leakage of fluid from the reservoir. I am hoping I won't have to replace that too.