I’m posting this to possibly help someone who had the same problem. What you’re seeing is the correct movement of the hydraulic levers on a Massey 175. Notice that the control valve (with the roller) goes beyond vertical in both directions. When roller moves to the right, it lowers the lift arms. To the left, raises. I bought this tractor a couple weeks ago, and they were stuck up all the time. The roller would not move to the right past the vertical position, even with roller removed. While roller was off, I took a long screwdriver from behind the tractor, set the tip of it behind the arm of the fork that the roller goes in and gave it a few hits with a hammer, until it broke free and started moving again. When this happened, it also added spring back pressure against the roller, which wasn’t there before. Hope this helps!