Service today, and one thing I mentioned was that when I wash the front windscreen wash/wipe, (pull lever towards me) the rear windscreen also gets a wash from the back water jet. Not as high powered as if I'm using the actual rear wash/wipe, but enough to hit the top of the back window (on a combi). It's annoying as I use proper fluid and at motorway speed because the rear hasn't had a wipe it then froths up in the air turbulence and can obscure the back window.

Garage (who said they couldn't reproduce the fault until I showed them straight off when I picked the car up) told me 'never seen that'. And they'll investigate but it means another trip back.

So has anyone else had this...what cause, and how did it get solved please?

Haven't seen this - can the angle of the jets be adjusted downwards? If the nozzles are attached to the bonnet, check whether the bonnet closing stops aren't set too far down too.

Are you saying water from the front jets is hitting the rear screen, or are you saying when operating the front washer jets the rear jet is also in operation (albeit less powerful)?

 

If it is water from the front jets then this is down to air turbulence. If stationary or moving slowly spray from the front washers on my hatchback can settle on the rear screen.

 

If water is running out of the rear jet without the rear wash being activated using the stalk then there is definitely a fault.

From the rear jet...at the same time as the front jets...

Never heard of this before - AFAIK both washers use the same pump in the wash bottle at the front, so a valve switches between front and rear nozzles. Sounds like this is where the problem is. It's also worth checking whether there's a software setting to synchronise both sprays just in case this is purely in software.

No software setting to enable "spray both front + rear when pulling lever for front" or something.

 

Sounds like a broken valve as Psycholist suggest. Get someone to scan the car for faults to see if something turns up, and take it back to the dealer!

To wind this one up...many thanks to my excellent local dealer Meadens. They swapped the washer pump without argument under guarantee (two and a half years) - took a couple of days to source. Completely solved the problem...now only the front or the back gets a dousing as I choose. I also realise now the pressure had fallen away - presumably as the pump was feeding two separate outlets, and now again it's an impressive wash. Just in case anyone else ever has the problem...

Result!

 

Thanks for remembering to update the thread to help other members!