I recently bought an 18' larson with a 99 merc 135 v6, after putting it in the water I discoverd a slow leak in the power trim. This is what I have observed so far. After using the boat I tilt the engine half way, just submerging the cavitation plate, in about two hours it will leak down a few inches but the not all the way down, it will stay in that position forever. I have done this multiple times and it continues to fall down only a couple inches. I have also noticed what I believe to be hydraulic fluid in the water around the motor. I have also noticed that it gets more in fluid in the water when a wave comes, I think its the upper seal, I think that because it only seems to leak when that seal gets wet. I have the trim with the ram and the two pistions mounted externaly on the transom between the mounts. Also it sounds like there is some air in the hydraulic system, as it doesnt sounds 100% lubricated. I have searched some forums, but found my symptoms to be different then other posts. Any help is greatly appreciated. Thanks.
Steve
Steve