w163 windscreen washers

joderest

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I thought all was going well with my ML270, but it had to throw something else up. At MOT time, washers seemed to dribble, so took all apart, used a hose pipe to test washers, good fan spray, no blockage, but when connected again just about wet screen. It passed its MOT, but they are not right.
I have bought a new pump as my thoughts are its getting weak, but then thought.......
Is there a non return valve fitted somewhere between pump and first washer ?, i cannot see one, but most of pipe hidden.

Any one know ?
 
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joderest

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going to reply to my own thread.
Yes there is a non return valve, located just before first washer. Took it off, cleaned it out, and refitted it. The pump pushes a good deal of water out when disconnected from non return valve, but connected up still the same, little water to screen.
The non return valve is quite tight, takes a lot of puff to blow through it.
So my first guess could be correct and pump is weak, it seems to pulse.
Now to take the skin off my hands and replace pump. if that does not work i will try and by pass valve, and it that works try to find a softer replacement or something.
 

EmilysDad

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This was exactly the problem with Emilys car a while ago, I'd replaced the pump and still had no joy. When I found the nrv I just replaced it with a joining piece .... problem solved.
 
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joderest

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thanks emilysdad.
The only thing that worries me is water getting to the screen as wipers wipe, would the delay of a non return valve missing mean no water to screen before wipers wipe (if you understand what i mean).
Quite happy to do away with the valve if it means a decent screen wash.
With valve disconnected and pipe sticking out side of car, washer pump pushed out water for a good meter and a half, very strongly.
 

daibevan

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just looked, loads on the bay, v cheap.
 
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joderest

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yep, could do, but may try it first without one fitted, if still the same must be the pump, which i already have, if without its good, will try another nrv. (i would like to keep one in the system.
 
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joderest

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I took out the non return valve and used a connector I had in my brake bleed kit. Lots of water to screen now. No delay which is nice.
I will put the new pump on and a new non return valve, but when weather warmer.
 

EmilysDad

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I took out the non return valve and used a connector I had in my brake bleed kit. Lots of water to screen now. No delay which is nice.
I will put the new pump on and a new non return valve, but when weather warmer.

As you've found out, you'll usually get away with it but it was never going to be a problem on Emily's cr4ppy Siecento .... the bottle & screen were only a few feet apart :D
 
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joderest

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ok, back to sq one
The jet onto screen is great on passenger side, nothing in middle and poor on drivers side.
I have fitted a new pump, no change.
used a hose to clear jets, no change.
I think its an internal issue with the washer jets, but i am not going to fork out £160 for screen washers !!!!!
does anyone know how to take out the insert in the jet ?
failing that, i may just bodge after market pin hole ones on to the car.
does any one have a fix ?
 
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joderest

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Well, what do you know, me it appears not a lot!!!!
Today, took all three jets out ,of car. Blew them out with a hose pipe. All three had a good spray pattern. Put them all back. Still no water to screen. Took them out again and fitted each in turn direct to end of pipe from pump, all three were good. Put them back, nope, nothing. It then dawned on me that although there was no spray to screen there was loads of water draining out of scuttle, and washer tank going down very fast. THEN LIGHT BULB MOMENT. Replaced the pipe from passenger jet to middle one with some plastic pipe I had in the shed, hey presto. Working screen wash. The pipe must have a split in it. I will have to have the scuttle fittings out in the summer to make a proper job, but for rest of winter I can now wash the screen. DOH !!!!!!
 


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