Does it work this way?
I've been spending a bit of time trying to figure out how the system actually works. And, I think I know why many of the cars that I've ever come across had a system failure. But, any correction would be appreciated and encouraged.
Some have stated that air being pushed by the rubber pump/bulb/bellows across the T on top of the reservoir causes the fluid to be sucked up into the washer line. This is shown in the first diagram posted by in #5...kind of like the action of siphon paint spray guns. IDK...I would think that you would need a lot more air to go across a T to draw up the liquid. I think it works a different way.
The pump does push, but it also sucks when released by your foot. My GT works this way...After filling up the reservoir/tank and hooking up the line to the foot pump, the rubber bellows inside the foot pump will actually fill up with fluid after several pumps of the foot. Then, when the foot pump is pushed, it starts to force fluid up the line to the nozzles in the hood. If washer fluid wasn't wanted in the bellows, there would be a check valve in the line between the reservoir and the foot pump. But, a one way valve in that line wouldn't allow the bellows/bulb to expand again.
Moving to the line between the reservoir and the nozzles...The check valves are placed near the nozzles so that there is always fluid near them (the nozzles) and to prevent backflow between the nozzles and the reservoir.
I've tried to use a 3 way aquarium T with equal sized ports. The system wouldn't work. The original Opel T has a smaller port that goes into the reservoir. The smaller port must help to direct the fluid to the line of the nozzles. This is how the system works...Stepping on the foot pump, puts pressure in the system and forces fluid in the pump across the T and into the line to the nozzles. When the foot comes off, the check valves prevent backflow in that line. The expansion of the rubber bulb draws fluid from the reservoir.
The reason that rubber bellows frequently fail is because they get old and leak like most rubber parts do. I've seen most of the leaks are on the neck of the bulb that extends out of the foot pump. The leakage will allow air into the bulb which prevents the system from working and will eventual lead to the rusting out of the metal washer that seals the bulb to the spring loaded pump housing.
IDK...maybe a leaking check valve could lead to system failure too. Most of the original valves that I've come across don't work. Aquarium check valves can be bought at a pet store or even Walmart for a couple dollars each. And, you probably just need one placed somewhere between the reservoir and the line split to the nozzles. I would try OGTS for the replacement rubber bulb/pump/bellows.
