I have a Sea Ray with a 135 Mercury outboard. I had just replaces the stator and rectifier for a no start and charging problem. It ran great for about a mile, then when I went to adjust the trim, it would go up but not down. I stopped and checked it out. Up trim works just like it always did. When trying down trim, the motor runs, and the tilt moves just a tad, then stops moving, but the pump still is pumping. <br />I assume I have an internal leak, as occasionally it will trim down fairly quickly. I pulled the port trim piston, and checked the check valve like the Mercury manual said. It appears to be free, but looks like a double check valve, and I can't spray carb cleaner through it. Put it back in and same problem. Mercury manual says there are check valves on the tilt ram, but I assume they are in case you hit something.<br />Any ideas on what to look for next. Mercury dealer stocks the pump seal kit for $14.00, but not sure if I am looking in the right place for the problem. New trim/tilt is $960.00 from Mercury, so would like to fix it if possible.