I recently got a 2020 gas tractor, long story short. We replaced to engine and upgraded to a 219 diesel. It runs great, lots of power.
However, the hydraulics work great until it warms up (rear remote, and 145 loader). When pulling a bush hog after about 30 minutes it loses its lift and by that I mean it lifts the mower slower and slower until it wont lift at all. The loader will lift as it should until the hydraulic fluid warms up then loses its lift also. It will drop running wide open, about a foot or two every few minutes then not lifting at all. Also when sitting on flat ground about half throttle the front tires will slowly turn right.
I changed the fluid, put in new filter and cleaned the screen. The screen had sludge and yellow paint. (side note - the book says it takes 10 gallons, in reality mine only took about 6-7 with the loader on after I raised and lowered it about 10 times). I also had a steering column leak and replaced the 6 o-rings inside, top seal and o-ring under the steering wheel. Also cleaned the screen on the front pump.
And still have the same problems.
So now I'm thinking the relief valves aren't closing, or an internal leak. I looked inside the filler cap and see no fluid moving around at any rpm. I haven't done any pressure tests yet. I don't have the shop book to give me a direction to go from here.
So now what? Any guidance is greatly appreciated, and thanks in advance.