I have a 2004 TC35 (NOT HST) (500Hr on it) with a 16LA loader.
The loader has started to surge or rase about 3-4 in then stop then go 3-4 more to full hight, fluid is full, filter chaged about 1 mon ago. Where is a good place to start looking for the problem?
It's stupid simple, but easy to check the selector (valve?) on the right side of the tractor where the lines to the FEL valve body attach. Seems like the screw has to be turned to the front position to feed the FEL. IDK if it opens an additional circuit or not, but with it at 75% position the FEL on a TC29 was slow & had no power. Like I said, easy check.
I still have full power on the loader it just surges. I have a rear remote running a grapple bucket and it surges to so I don't thinks it's the FEL. It sounds like the pump is starving for fluid, and it is full of the right fluid & new filter.