This is just the latest in brainstorms on how to indicate the position of the TNT cylinders. The hose plugged into the QD at the bottom of the sight gauge goes to the base end of the tilt cylinder. It's normally plugged into the tilt valve along with the rod end hose.
The tilt cylinder becomes, in essence, a single acting cylinder which works for the same reason that the 3PH cylinder is single acting. The sight tube is open at the top end to accept a breather same as normally used on a double acting cylinder when used with a single acting valve. I'm thinking, however, that it (sight tube) could be plugged when the tilt cylinder is fully retracted to fill the sight tube. It would then pull a vacuum when the tilt cylinder is extended but not sure how much vacuum. Will have to give that a try and probably depends on how much extra capacity in the tube.
The sight tube is 1" inside diameter which requires 9" of length to accept volume of the 1 1/2" x 4" stroke tilt cylinder. I did cut the tube a couple inches extra length for that purpose. The plastic sight tube would be mounted inside a metal shield for protection. The shield would have a slot to allow a visual on the fluid level.
Would like some constructive criticism of thisidea. I realize that not everyone is going see it as useful or practical.