Windshield washer T connect

[Wenski]

I have an ‘88 Carrera with windshield sprayers only. No headlight intensive washer system. The pump is new and new check valves replaced below the nozzles. When I try and spray the flow is very low to the windows. When I disconnect the return hose to the reservoir tank at the T connector beside the pump and block it off the pressure to the window is good. Why does the pump have a return hose? Is there something in the T connector I am missing. Is there something in the tank at the end of the return hose I am missing? Do I need to have the return reservoir hose?

[917_Langheck]

Check the PET diagram for the layout. Search the 'net for "1988 Porsche PET" and you should find a link to the pdf catalog.

[EC900]

I believe it’s the L valve (pass side) and the T- valve (driver side) are actually check valves that lead to the two nozzle jets that get clogged, or inoperable that will impede the washer fluid. The check valves hold and keep fluid/pressure in the lines so the washer fluid draw doesn’t travel as far (from tank to the nozzle).

I think you need to disconnect the T at the pump and give both lines a good blast of compressed air to clean out the line and the pinhole nozzles. Better to do this further up the line, closer to the windshield, note along fender you will find a hard vinyl line connects to soft line. If you do this, paper towel the nozzles so spray doesn’t go all over. A bit of de-scaling agent like Lime-A-way will break down scale but may also cause bits to further clog. So it’s a repeating process to clean so I replaced the flexible washer lines which were yellowed and partially collapsed. I removed tank and cleaned it but surprisingly 45 yrs of stagnant washer fluid wasn’t the problem and there was very little if any contaminants inside. Problem seems to be old lines. The actual pump is cleanable too, easy enough to disassemble, it was a bit calcified.

There is probably some scale and sludge that is restricting the flow and new L &T check valves may be needed, I’ve managed to clean mine, plus used a pin to clean and align the nozzle jets.
It’s a tight and tedious process, but eventually replaced the L and T check valves but added a few more inches from the nozzle in case they get clogged again.

Yes you’ll need the T line (return) at the pump it will leak w/o, and a PET diagram.

[Wenski]

Thanks for the help I now have the diagram and working on the T line joint to make sure the return works.