</font><font color="blue" class="small">( I'm pretty sure somebody will differ on the hyd. level changing, so I might as well be the one. )</font>
Don't worry, I am not someone that expects everyone to agree with me. I have been on these boards much too long for that. /forums/images/graemlins/wink.gif
Yes, the cylinder are double acting, but when they are compressed, arm inside, they use less hyd fluid. ie the rod itself takes up space. I couldn't find any of those cute little java demos, this AM, it would be easy to see.
In the mean time, here is the test you can do: Warm your tractor up, raise fel fully and extend bucket fully. Fill hyd tank to the top and run a hose off the vent to a clean gallon jug. Retract bucket and fel and measure hyd oil in container. You will see it is more than just a few teaspoons.
BTW, I was only indicating which of the vents probably has the most air exchange. Even as the oil heats up, the level rises. How much air exchange, I never tried to calculate or measure.
BTW2, we have a wasp that has the same habbits! /forums/images/graemlins/crazy.gif