Vito van rear window washer not working (Blocked?)

[Alans dad]

I have just got a 2005 2.1 Vito109cdi LWB van. The rear window washer jet is not working. I have checked the pump by disconnecting the ribbed hose at the reservoir and that is fine and squirts water out with a good pressure. The ribbed pipe/hose then disappears up behind the bulk head and does not reappear until the rear door hinge where it is bundled together with the wiring loom. I have disconnected the short rubbery hose from the rear wiper and no water comes out so the problem is not a blocked wiper jet. Ergo the problem lies between the wiper jet and the pump. Are there any valves or accessible joints in the hose? Are there any points where the hose might get pinched or kinked? Is this a common fault and how easy is it to fix or put a new hose in?
Thanks for any help on this.

 

[Phil Brown]

I have just got a 2005 2.1 Vito109cdi LWB van. The rear window washer jet is not working. I have checked the pump by disconnecting the ribbed hose at the reservoir and that is fine and squirts water out with a good pressure. The ribbed pipe/hose then disappears up behind the bulk head and does not reappear until the rear door hinge where it is bundled together with the wiring loom. I have disconnected the short rubbery hose from the rear wiper and no water comes out so the problem is not a blocked wiper jet. Ergo the problem lies between the wiper jet and the pump. Are there any valves or accessible joints in the hose? Are there any points where the hose might get pinched or kinked? Is this a common fault and how easy is it to fix or put a new hose in?
Thanks for any help on this.

Hello, I just fixed mine today 19/10/19 on a Vito 220 CDI Dualiner 2010 which is likely the same on your Vito 109cdi. There is a joint located under a removable panel on the RH Rear Quarter on the inside of the vehicle, by the RH Stop Light/Winker Light assembly. The joint can be forced apart in freezing weather conditions or if blocked at the jet. A possible solution to prevent this happening in the future is to make sure that in the winter the washer fluid is a strong enough mix to prevent freezing down to -10C. I noticed water lower down the same area dripping after I had removed the lower panel trying to find the washer pipe, and also you would find the water level in the washer reservoir is going down, (when you operate the rear washer switch) indicating water is going somewhere. You will probably see water underneath the vehicle near or just behind the rear offside wheel. Note I have a dualiner with the comfort package so there is a plastic car like interior all round the inside of the load area, hence having to remove panels for access. Standard vans may have direct access without having to move any panels.

The washer pipe is braided together with the wiring loom, so you won't see a plastic pipe on its own, which initially confused me. The pipe is routed along the inside low down, rather than at roof height, and comes up to a joint behind the RH Stop Light/Winker Light assembly. The braided wiring loom containing the washer wipe is tucked behind metal work that forms a chanel/protected area behind the RH Stop Light/Winker Light assembly. If you fish around a bit and gently and firmly pull the braided wiring loom you will find the washer pipe joint. Push the pipe firmly back onto the joint, and the rear washer should function. One last point, when the tailgate is open (if you have one) the rear washer doesn't work, and the ignition must be switched on and the rear washer button depressed before it will function. I hope the above provides a nice lucid solution that will take about half an hour to fix.

 

[Alans dad]

I forgot to say what happened in the end. The hose ends up going into the rear wiper mechanism behind the panel of the rear door. When I removed and dismantled the wiper motor gear mechanism I found it was full of water and sludge. Seemed like a silly design to me to pass the water through this moving part so I decided to bypass the wiper mechanism. I drilled a small hole through back door near the wiper and passed a length of aquarium air hose through it. Using a little connector (bought on ebay for about 30 pence) I connected to the original Mercedes hose inside the door and plugged the other end into the wiper on the outside. I had to have about 6 inches of excess hose on the outside to allow for the movement of the wiper blade. It works fine. I have been meaning to add a rubber grommet and some anti rust paint to the hole I drilled but have never got round to it. It hasn't cut through the hose or showed any signs of rust so it will probably stay like that.