My boss just bought an old Thomas 233hd skidsteer, it runs surprisingly well, just one problem we can figure out, when you use the hydraulics if you press back on the bucket tilt pedal to tip it up, there is no response unless I step on the boom pedal at the same time. If you let go of the boom pedal the bucket will stay tilted up until you let go of the tilt pedal, and when you do it crashes to the floor, I have gone through and checked for stuck linkages and valves everything looks good, none of the hoses are missing rerouted or tampered with in any way, checked against the service manual, not sure what could be wrong but any ideas would be greatly appreciated
A T233HD is a good machine. The earlier T233Plus had some issues. Make sure the aux. hyd. pedal isn't engaged. If that's fine I'm wondering if something is wrong inside the self leveling valve that automatically tilts the bucket as you lift. I think it was standard on a 233HD. Main control valve may need some seals is another possibilty. If it's like a 133 the self level valve can be disconnected by removing some hoses but I'm not sure what all is involved to hook things up without the self level valve. Also if it's like a 133 there is an adjustment on the self level valve that basically turns it off. If you google Thomas loaders there used to be the manuals listed you could look at. A couple former Thomas employee's started a company to provide parts and built small stand on loaders. They were recently bought by Ariens of snowthrower fame.
Thought of something else that is much simpler. With the boom down will the bucket tilt down by itself? If not what happens if you lift the boom while tilting the bucket back and shut the machine off and then letting off the pedals? If the boom stays up but the bucket falls down the seals in the tilt cylinders could be in really bad shape and need replacing.