the hole next to the marked one (on right) is also a port... air will come out of a bolt hole too.
There are 3 rubber seals on the piston in the case. that creates 2 sections on the piston. One is reverse , the other section is used for manual 1st gear
Some people are like Slinkies... Not really good for anything, but they still bring a smile to your face when you push them down a flight of stairs.