The brief
The A4's windscreen washers weren't working properly, the fluid not spraying or coming out weak and uneven, with an unusual noise when the washers were activated and a visible leak around the pump. He brought it in, a screen you can't clean is a visibility problem. The washer pump sits at the base of the reservoir and pushes fluid up to the nozzles with enough pressure to fan it across the glass. When it wears, it can't make that pressure, so you get the weak, uneven spray and the straining noise, and a tired seal or bush at the pump lets fluid weep out, which is the leak. A washer pump doing that has had its run, and it needs changing rather than living with a screen that won't clean.
The diagnosis
The reservoir held fluid and the lines were clear, but the washer pump was running weak, drawing current and barely moving fluid, with a weep at its seal. So it was the pump at fault. The nozzles had also collected some grime to clear while everything was apart. That's a pump replacement plus a nozzle clean. A worn washer pump only gets weaker, so it was getting changed.
The work
The old washer pump was pulled from the base of the reservoir, the seal area cleaned, and a new genuine Audi-spec pump fitted with a fresh grommet so it didn't weep. The nozzles were cleared and aimed, the lines reconnected, and the system run to confirm a proper fan of fluid across the screen on both passes. A quick check confirmed strong, even spray, the nozzles aimed properly, and a dry reservoir base.
The outcome
Strong, even washer spray across the screen, the nozzles aimed properly, no leak at the reservoir, and no noise. The A4 went home with clear vision on demand again. A weak washer pump is easy to live with until the day you really need it, so swapping it and clearing the nozzles got the whole system working the way it should.