Hey guys
So I small thing, probably a system I'll hardly use anyway but one step closer to a fully functioning car right? I've been working on getting my 55's foot-pumped windshield washer squirter working. I replaced all of the lines, used hose clamps to insure no leaks, and checked the rubber pump to make sure it's not cracked and leaking either. I took it out of of the car, covered up the opening to the pump, depressed it and watched to see if the rubber 'bag' would reinflate indicating a leak in it.. it did not it held in it's deflated state until I removed my finger from the opening.

Pumping it now, I hear air rushing out of the hood squirter but no fluid comes out. I understand the system, the bag is pressurized until fluid is forced out the only open hose (the nozzle). My bag isn't pressurizing, and I found that the leak is in the bag's cap, if I press down on the bag then fluid will dribble out from around the twist-on cap. I'm assuming I need to install some sort of thin gasket up in the cap but I'm looking at new factory bladder bags and their caps don't have any kind of gasket so I'm curious if a gasket is really what I need.

What are your guy's thoughts?