Windscreen washer jets

[Razor61]

Replaced both washer valves on my 2010 IS250 today to cure a ‘low pressure’ type issue on the drivers side.

Symptoms: low pressure on drivers side windscreen washer - I knew the pump was ok as the passenger side was fine. The wiper was ‘wiping’ before the water had chance to hit the windscreen and when it did there wasn’t enough water. I had bought new wiper blades but wasn’t going to fit them until the washers were working as they should.

Diags: removed the drivers side jet assy, checked it and it seemed ok. Removed the bonnet insulation, removed the pipe work to both washer jets. There is a one way valve for both drivers side and passenger side washer jets. Checked the one way valves and the passenger side was working, I could blow through the valve one way only but the drivers side I could blow through and suck water back the other way which shouldn’t happen. So the problem looked like it was the one way valve, common issue I think on a lot of cars.

Fix: ordered 2 new one way valves from LPD - part number 85321-26020 - fitted the drivers side and tested - drivers side washer now worked as it should - passenger side was working ok but now was not as good as the drivers side - fitted a new one way valve on the passenger side as well and both are working as they should.

Notes: be careful removing the washer jets as you tend to bend the rear plastic retaining tab to get them off. Just bend it back to where it should be otherwise the washer jet assy is loose and drops down at the back. The washer jet stream then hits the underside of the bonnet, I know because I did it. Order a few of the trim clips for the bonnet insulation as some of them may break removing them - part number 90467-09050 (generic clips and these are listed for a CT200)

I believe the one way washer valve going faulty can cause the same issue as mine or not working at all on one side or both sides.