When I bought my car in September last year, the window washer system was clogged to the point of no water coming out. I initially thought it was empty.

Then I read up a bit on this forum to find out that it is not an unusual problem. What bothered me was that the bottle is hidden deep in the engine compartment, and the suggested fix was to remove the front bumper to gain access to the pump for cleaning.
I thought I'd try anything & everything before I try to remove the bumper.

So my first step was this:
(my car is RHD). On the driver side, below the rear cover in the engine compartment right up at the window (where the brake fluid reservoir also is), there is a T-junction where a rubber pipe splits into the 2 wiper blade water feeds (see first photo). (Initially I thought these thin tubes and/or the jets on the wipers might be the problem). I unplugged this and forced water in all directions. Soon I learned that the jets are OK, and that there must be sludge in the water bottle because you can blow back (garden hose or breath), and then it pumps marginally better for a short while before clogging again.



So the problem was definitely down in the water reservoir where I cannot reach.
My Next Step:
I emptied the reservoir as much as I could (poor pump – did you know it cuts out after a certain time of suffering, then you have to wait or switch ignition off/on again). I wanted to use caustic soda to dissolve/dislodge the muck in the bottom. A little dangerous if not done carefully, and I didn't want any of it anywhere on the car. So I noticed that my garden's microjet irrigation fittings fit exactly onto the wiper water hose. (In photo 1 you can see my irrigation extension tube plugged into the car's feeder tube). So I poured a measured amount of caustic soda water solution into the water reservoir, and pumped it out via the washer pump and clear of the car, back into my exact measuring device (see photo 2). This worked in the sense that I did see some impurities empty into the beer bottle, but in general it didn't actually help much and it still clogged frequently, requiring me to blow back.

So my Next Step:
Stick a thicker tube right down into the reservoir, through all the bends, to as far as it would go, and siphon out the gunk directly.




This did suck out some of the exact flaky yuck I imagined would be in there. The tube had some kinks and jammed, so I went to get a thicker tube, which worked even better.
Now, as I did not want the siphon to stop when the water level dropped, I occasionally squirted some new water down into the reservoir with the garden hose. I noticed that each time I did this a fresh splurge of junk came out via the tube, so I was stirring it up nicely. So the obvious next step was to blow in water through the extra tube deep down inside the reservoir, to hopefully dislodge more of the gunk (see last photo). This also worked nicely.




This also worked nicely. While siphoning I occasionally also blew water back via the window washer tube, to dislodge anything stuck in the pump / little filter mesh it might have.
After a while it (the siphon) ran clear so I called it quits.
Now, a few months later, I am fairly certain that I did get it all out, since I don't have problems at all.

Hope this can save someone from removing a bumper!

Thanks

 

That's using your head, nice work.

 

I have recently purchased a beat up ‘05 XJR and thought I was going to have to buy a new pump…you have my hopes up that this might be the issue instead…can’t wait to get home and give this a try.

THANKS,

max

 

I forgot to say - I think the weak caustic soda mix may still have a role to play.
Being a "super soap" it can dislodge & break up the crap. Let it sit for a while before "flushing"

Also, I wonder how much of the problem is due to the fact that the blue cap on the reservoir doesn't seal - it just lies there. Also no filter to catch big impurities when filling up. In contrast my Audi & VW have little "filters" in the neck, and the blue lid clicks shut properly

 

Order a cap that fits, with your next parts order.
Use electricians tape to keep the lid shut till then.

 

?
soda mix being a baking soda and water ?

 

Wonder if he is talking about a solution of sodium hydroxide, or lye.

 

Caustic Soda is a major component of e.g. drain cleaner, but can be bought on its own in our hardware shops (South Africa). My tin does not say what is actually inside, but wikipedia seems to say that Caustic Soda & Lye are Sodium Hydroxide, NaOH.
It is caustic (corrosive) , but also super soapy, and can dislodge gunk deposits like what was in my washer wiper reservoir.
That's why I made sure to not get any of it anywhere else on the car (plastic & glass are OK with it)
I use it to clean beer bottles when someone didn't clean it while still wet (I'm a home brewer).
Don't get it on your skin - if you feel that soapy feeling, it is apparently the fat in your skin turning into soap, time to rinse vigorously
I make a weak solution ( 1/2 tsp to 500ml water), then contact time is also a factor - weaker for longer gives you more control

 

Thanks, I assumed they're all like mine - sits on top but does not click shut. When I checked closer, it almost seems as if the cap is marginally too big, or something is missing which would've made it seal shut properly.

 

Thats what i thought, it can be nasty stuff;
Used to make up 13% NAOH solutions, from 55 pound bags.
When i worked an hourly job at a major Chemical plant, years ago.
Took some home before to pour in the drain.
Still have some in powder form on a shelf


Yes it dissolves the fat in your skin on contact.
Mixed it with HOT melted, filtered, animal fat.
Very often they used hog fat, from their slaughter
Poured the solution into molds, to make bars of soap.
Letting them cure for a while, to solidify, or harden.
That's how our ancestors, made soap at home.