I am going to guestimate, since I've never measured it, that the windshield reservoir holds about a quart, 32 ounces. It also evaporates pretty dang fast. If you're using the blue stuff, it's 50/50 water/methanol. And as we all know, any type of alcohol evaporates readily. Anyway, I rarely ever use that function, don't drive it in bad weather. I just keep it full, jic.
There are no fittings on the tank anywhere except the inboard side (driver's side). There is no room on the back surface due to proximity to the battery. The front and outboard side obviously would be difficult to put things.
The inflow fitting is top center, the outflow hose is bottom center of the inter-cooler reservoir area, and the washer pump is at the bottom rear of the whole shebang. I look at it in this way: If I could put it in my truck, anyone should be able to. Hard to take clear pictures of all this due to all the a/c hoses and fittings that are very near the tank.
Some people had trouble getting the tank into the truck, others such as myself did not. Hit or miss I guess. Hard to blame JLP for this as it is a Ford production tolerance issue. No two trucks are exactly alike. JLP cannot be faulted for this. I just know, were I to sell this truck and buy another, I would buy another JLP tank, no questions asked, and make it fit. It's about as big a tank as you can put in that area, due to the battery. Only way to get bigger is to get the race version, and forget about the washer reservoir. I also have their radiator overflow tank with custom lid, and their sheet metal plenum. All good stuff.
I think this one covers it though. View looking down at the inboard side. You can see the pump on the left, with what appears to be a braided hose. The inflow hose right in your face. The outflow hose down beneath it. Best I can do, with all the clutter there.
Also included a picture with the new cap in place. My original one leaked pretty bad, and had to clean the top often. The new one has a much improved and tighter fit, with a reinforcement ring that goes inside the tank. The original did not have the reinforcement ring, and thus there were gaps between the fasteners that allowed fluid to seep out. I believe that JLP has addressed this issue though, and shouldn't be a problem. I mainly changed it because I wanted the red.