Windshield washer system

[sleeping_beast]

Hi,

I'm actually rebuilding the windshield washer system on my '75 911. On the reservoir, there is a cap with three tubes. One tube seems to be a vent. The second one goes down in the tank and has a valve. It seems that this one goes directly to the pump.

On the other side of the pump, there is a T junction. One of the T junction output tubes goes to the jets while the other one is the third tube that goes back to the reservoir cap. Why is there such a T junction at the output of the pump with a tube going back to the reservoir cap?

Thanks,

Alain

[sleeping_beast]

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[5speed]

I think it act's like a pressure valve. If there is a blockage then the pressure goes back to the reservoir. At least that's my opinion.

[sleeping_beast]

Hello 5speed,

That is also my opinion but I'd like to find the answer without any doubt. If I had designed this system, I don't think I would have had this return tube. What would have happen in case of clogged jets? Pressure would have built in the tubing but what else? Would the pump burn?

Thanks for your reply,

Alain