My BX25d with about 33 hours on the meter was making a funny noise when I lifted my 3 point hitch all the way or curled or dumped the bucket all the way. I had been running the tractor for several hours doing some driveway leveling. I checked the hydraulic fluid and saw lots of foam. I let it cool down, checked it again after the foam was gone and the level seem fine. Ran the tractor around the shop and looked again and he foaming was starting to show again. Anything I should look for? Is this normal?