I know it was in the ask the experts section but the thing I hate is that I cannot post to it!
Just for your information when you select “ask the experts” it will not allow any other forum member to post except for the real IFI guys or the “experts”. For some questions its better to ask there but for a general question like this just ask in the main forum and you will most likely get answers much faster.
You can refill the air reservoir from the shrader valve that is included, that valve is more commonly known as a bike tire valve. Hand pumps or floor pumps from walmart will pump it up just fine, you can also use an air compresser with the proper attachment (bike tire valve) at 100psi to fill it up which only takes a second. If you use a bike pump try to get one with a pressure gauge on it because you do not want to go over 100psi as that is that max pressure for the regulators and valves on it, the tank could probably take a lot more but the other parts in the system won’t take more than 100psi.
Its all in the diagram of the pneumatics. In fact I uploaded an image of it and circled the tire valve for you. This is the single acting cylinder set but it is the same on the double acting set as well!
I hope this helps!
Hope this helps!