I have delved into what appears to be the forbidden area (as far as the Evinrude/Johnson workshop manual is concerned, and there are no questions I could find in this forum), of replacing the trim and tilt o'rings and wipers in my Johnson 140, 1980 model J140TLCSA with internal type trim & tilt. I did this because one of the trim cylinders was leaking and I did not want to spend a huge amount of money having experts replace a few dollars worth of rubber!<br /><br />On putting it all back together, and testing it on the boat, without the engine on (just the stern and swivel brackets), the trim cylinders aren't leaking, but fluid is pouring out of the trim cylinder, which didn't leak before! I guess that's what you get for disobeying the manual! I put the fluid in with all rods extended, then screwed on the resevoir plug, and pushed the swivel bracket down with my foot, so the rods were in as far as they can go. I then pressed the up button. The motor turned but nothing else happened for a while. I was able to top it up with a little more oil, and eventually the trim rods extended to their maximum, but then the tilt cylinder just leaked lots of fluid between the rod and the end cap. I have replaced all of the o'rings (including inside the end cap), and the rods and cylinders are clean and smooth. So my questions are:<br />. Can anyone provide me with a schematic showing how the hydraulics work in this (or any) tilt and trim? If I understand the theory, I've a better chance of determining where I went wrong.<br />. Is it really so difficult or dangerous to replace the internals of the tilt and trim cylinders that the amateur with reasonable mechanical skills really should not touch it?<br />. Any thoughts as to what I could have done wrong, assuming all the rubbers were replaced correctly, which I believe to be the case?