Has anybody got a diagram of the pipework for the washer system (my car is a Euro 86 if it makes a difference)?

This has been mucked around with in the past on my car. It all seems to work but the little reservoir for the strong fluid at the front is bypassed and there's loads of clear silicone tubing carelessly cable tied all over the place which just looks all wrong.

 

Here's info from from Tony's website: https://members.rennlist.com/v1uhoh/windshie.htm

 

Assuming that you want to restore the 'intensive washer' functionality, the diagrams at Tony's website are perfect. Note the check valves, which prevent backflow between the normal and intensive systems. There are steel ***** and springs inside, pieces that like to rust and clog, so the check valves really need to be considered consumables. The original hose is a fabric-reinforced soft poly, with black string in non-yellowed clear to translucent hose. Our US-based 928 parts suppliers have the valves, the Y-fittings, and the correct tubing in bulk. The plastic fitting where the two water circuits enter the hood is often damaged as you remove and replace the hoses, and is also a regular service part. The hose sections from reservoir/pump to that fitting are usually discolored at best, so deserve renewal with the rest of the pieces in the hood.

The hoses get stained with rust that starts at the steel sleeve that connects the filler neck part of the main reservoir to the reservoir itself. Many have removed that steel piece to solve the contamination problem, after cleaning any remnants from the reservoir and pump of course. Last I heard, the filler neck is showing NLA from Porsche. One of our inventors showed off a 3D-printed prototype of the neck at a recent gathering, something I'm looking forward to. The cap is still available from Porsche.

 

I imagine that's how all this started. The PO told me that he'd spent a lot of money getting the headlight washers working. This seemed odd considering that oil was leaking out faster than you could put it in but we all have our priorities!