Sometimes, when operating the front windscreen washers, I get a little squirt from the rear washer. it only happens occasionally - does no harm, but is a little "annoying". 

 

Anyone else had this leakage?

Not on the yeti.......however with age..!

I too have experienced unexpected leakage

I too have experienced unexpected leakage

Tena for men?

Tena for men?

 

I fear it's the only way

"little squirt at the rear" .................Where are you BobDog ?

Sometimes,  I get a little squirt from the rear

Anyone else had this leakage?

 

 

In Yorkshire it's called a Wet F@rt   

Poor Yety ! He comes on asking a sensible question and all he gets is 'toilet humour'!

It could be a little leak in the valve to the rear washer, caused by using hard water in the washer. Add some acetic acid or citric acid to the next lot of ww fluid - it might dissolve it.

 

It is a good idea to use distilled or de-mineralized water to mix the WW concentrate with. Condensate from a condensing clothes dryer is just fine too.

I've seen this on every car I've owned since about 2000. It's probably how the pump is designed: to save wiring and weight, most modern screen wash units use a single, reversible, centrifugal pump. It will have tangential exits on the clockwise and anti clockwise radii, one for the front screen, the other for the rear, the engineer preying on the fact that the fluid will see the path of least resistance. Spring loaded non return valves in each line increase the escape pressure required. So to get fluid to the back screen, the pump might spin clockwise, for the front, anti-clockwise.

I could foresee a moment where the pump spins up and pressure builds in the pump casing, but not enough to open the valves. It continues to build to the point where both valves open, the pressure falls off dramatically but then the pump starts to work properly - throwing fluid down the tube in the direction of rotation. The valve in that line remains open and the other line shuts. At the moment both valves open, you'll get some fluid ejected through all nozzles, this is what your seeing.

Dunno, it's a theory. Been a while since I did any fluid mech and I hated every moment of it (nasty horrible unfathomable maths).

It may also be deliberate to reduce the chances of the rear blade operating dry. The rear blade does come into action on its own when manoeuvring from start up -selecting reverse when the wipers are on.

Hydrographics? Not rocket science is it?

On the subject of squirts.....

The forecast of deluge on its way to the UK next week made me think. If I squirt car wash shampoo on top of the car, will the storm give it a high pressure wash?

I thought this was referring to little people in the back of the car, but obviously I was wrong!!!!     

I've seen this on every car I've owned since about 2000. It's probably how the pump is designed: to save wiring and weight, most modern screen wash units use a single, reversible, centrifugal pump. It will have tangential exits on the clockwise and anti clockwise radii, one for the front screen, the other for the rear, the engineer preying on the fact that the fluid will see the path of least resistance. Spring loaded non return valves in each line increase the escape pressure required. So to get fluid to the back screen, the pump might spin clockwise, for the front, anti-clockwise.

I could foresee a moment where the pump spins up and pressure builds in the pump casing, but not enough to open the valves. It continues to build to the point where both valves open, the pressure falls off dramatically but then the pump starts to work properly - throwing fluid down the tube in the direction of rotation. The valve in that line remains open and the other line shuts. At the moment both valves open, you'll get some fluid ejected through all nozzles, this is what your seeing.

Dunno, it's a theory. Been a while since I did any fluid mech and I hated every moment of it (nasty horrible unfathomable maths).

 

Thanks, first sensible reply!

 

Do we know what sort of pump/s we have on Yetis?

 

Also, it could be, as suggested, crud in the system interfering with one way valves as well?