What type of fluid is in my trim tab resevoir? noticed last weekend they seemed to be laboring a bit when the boat was out of the water and trimming up. then looked in the little resevoir and noticed fluid about 1/2" low. Could this be the problem with the slow performance? seems to me that they should work even though the resevoir is low. need to replace fluid, what do I use? Oh by the way, it's a 2001 2100.