check and make sure the breather is open, and if for some reason water could haven gotten into the trans, if there is any water in the trans it gonna boil it out of the dip stick. some people wash their parts off with water and get more into the conv. than they realize, if you let it run it will eventually boil all of the water out. if it locks up in gear i dont see how you could have a pressure leak. filter might be to close to the pan. hope this helps